Significant Tension Research Articles

Smuggled Doughnuts and Forbidden Fried Chicken: Addressing Tensions around Family and Food Restrictions in Hospitals.

It is a common practice for family members to bring food to hospitalized loved ones. However, in some cases, this food contravenes a patient's dietary plan. Such situations can create significant tension and distrust between health care professionals and families and may lead the former to doubt a family's willingness or ability to support patient recovery. This case-study essay offers an ethical analysis of these situations. We draw on Hilde Lindemann's work to argue that providing food to family members is an important way that families discharge their moral functions of caring for their members and holding them in their identities. When family members are hospitalized, other means of performing these functions are limited. Acknowledging the ethical importance of feeding family members alongside the medical need for dietary restrictions, we offer strategies for creative problem-solving that center diet as a subject for shared decision-making and regular, ongoing communication among health care professionals, patients, and families.

Structural behavior of steel tie connections in masonry veneer walls: Proposal of a simplified approach for practice

Steel ties perform a key structural role in ensuring the stability of buildings façades built with brick masonry veneer walls. These elements are responsible for transferring the loads acting on the veneer wall to the main structure, which typically consists of masonry infill walls used in reinforced concrete frames buildings. Such constructive system is common in Portugal and other Mediterranean countries where the seismic hazard is high. In the event of an earthquake, the ties have to transfer the out-of-plane loads and are subjected to significant tension and compression stress. The characterization of the seismic behavior of these tie connections is an insufficiently explored topic. Despite the codes available for the design of brick masonry veneers and ties, recent earthquakes brought to light the seismic vulnerability of this constructive system. The present paper proposes a simplified spring numerical model validated with experimental results. The simplified model can be applied to perform numerical analyses of greater scale (e.g. to analyze full façades of buildings), which can help to optimize the design. Finally, the paper identifies a common construction problem, which is the probable misalignment of the mortar joints of the masonry walls. A construction solution is proposed by the authors.

Infraclavicular de novo placement of a responsive neurostimulator for a patient with eloquent glioma-associated epilepsy: illustrative case.

The authors present a 50-year-old female with high-grade glioma involving the motor cortex as the cause of her drug-resistant epilepsy (DRE). Responsive neurostimulation (RNS) was chosen for epilepsy treatment. Due to concerns regarding the generator impeding the regular imaging surveillance required for treatment and monitoring of her glioma, surgeons placed the internal pulse generator (IPG) within an infraclavicular chest pocket. Implantation of the RNS device and IPG within the infraclavicular pocket was uneventful. However, both subdural and depth electrodes were used and connected to the IPG, and subdural electrodes are considerably shorter than depth electrodes (37 vs 44 cm). The shorter strip leads presumably generated significant tension, leading to fracture of the leads. Therefore, surgery was repeated using only depth electrodes for more length and less tension. The device has good-quality electrocorticography signals that continue to be used for device programming. The seizure burden was reduced, and quality of life improved for the patient. The RNS system with infraclavicular IPG placement reduced the seizure burden and improved the quality of life of a patient with glioma-associated epilepsy. Surgeons may consider the infraclavicular location as an alternative site for implantation for RNS candidates who require recurrent intracranial magnetic resonance imaging.

Multiscale characterization and modeling of aggregate contact effects on asphalt concrete’s tension–compression asymmetry

Asphalt concrete (AC) exhibits significant tension–compression (TC) asymmetry and aggregate contacts can be one of the critical contributors to this behavior. Nevertheless, the underlying mechanisms are still unclear, and there has been no study to quantify this behavior. To fill the research gap, multiscale characterization and modeling on AC were performed in this study. At the microscale level, nanoindentation tests were conducted to characterize the aggregate contact characteristics in the contact region (CR). The CR was found to have a sandwich-like structure consisting of two interfacial layers, large filler particles, and asphalt mastic. Accordingly, micromechanical models of CR were developed to predict its mechanical behavior in tension and compresison (T&C). The modeling results showed that aggregate contacts significantly increase the compressive modulus, leading to the substantial TC asymmetry of CR. The predicted viscoelastic properties of CR were further applied to the developed mesostructural model of AC. The predicted master curves in T&C showed significant asymmetry and quantitatively agreed with the experimental ones, demonstrating the effectiveness of the adopted modeling approaches. This study is the first study to quantify the asymmetric performance of AC. The outcomes can be applied to evaluate AC’s TC asymmetry effects on pavement performance.

Evaluation of the efficiency and safety of Esmolol in patients, who suffers from hypertensic crisis, within the conditions of emergency medical care

In 94 patients, suffering from complicated or uncomplicated hypertensic crisis, the efficiency and safety of esmolol administration in pre-hospital stage of emergency medical care was examined. Unique pharmacokinetics of esmolol allow us to achieve significant arterial tension decrease during the first minutes of the intravenous injection, meanwhile antihypertensive effect increases till 20 minutes and elimination half-life is 9 minutes. Esmolol dosage was selected depending on initial hemodynamic indicators and hypertensic crisis complications. In order to evaluate efficiency and safety in this research the following indicators were measured: sistolic blood pressure, diastolic blood pressure, heart rate, electrocardiogram and SpO2 , respiratory function monitoring.

Performance of rocking frames with friction tension-only devices

The implementation of a new friction tension-only “GripNGrab” device attached to a rocking steel frame is described. The device, when subject to significant tension dissipates energy via sliding in the frictional component. When the device is loaded in the compression direction, almost no compressive force is carried, but displacement occurs in the ratchetting component. This absence of any significant compressive force within the dissipative system means that the rocking frame will always recentre after uplift from earthquake shaking. A 9 m tall 4.75m wide 3-storey steel concentrically braced rocking frame is designed for low-damage seismic performance. Restoring forces are provided by (i) gravity, (ii) friction “GripNGrab” (GNG) tension-only dissipation devices at the base, and (iii) beam-slab effects. The initial fundamental period of the structure was 0.16s. The initial structure used a 10mm GNG ratchet pitch, and had a GNG strength to not slide under serviceability level shaking. Elastic, pushover, cyclic pushover, as well as time history analyses, with different shaking intensities are conducted using OpenSEES software. The scope of work is limited to a single building and a single ground motion. Parameters varied included the presence of beam-slab effects, and the GNG device stiffness, strength and tooth pitch. It is shown that the full behaviour of the frame could be understood considering cyclic pushover analysis. The peak uplift displacement was conservatively estimated from the peak roof displacement using rigid body mechanics and the tension-only device provided no resistance to full frame recentring. For the frames considered, cumulative uplift displacements, necessary to determine the inelastic displacement capacity of the tension only device, were up to 28 times the peak uplift displacement, not necessarily occurring at the maximum shaking intensity. Maximum frame base shear force demands were up to 1.43 times that from pushover analysis. When the beam-slab, connecting the rocking frame to the rest of the structure, increased the lateral force resistance, the base shear increased significantly, reduced peak roof displacements, and increased the effective number of peak uplift displacement cycles (NPUDc). For large shaking intensities, yielding of the beam-slab occurred resulting in permanent peak roof and uplift displacements. The GNG device strength, stiffness and tooth pitch variations for the cases studied did not significantly affect the response. Initial stiffness, and secant stiffness, based methods to predict the response of rocking frames were non-conservative for these short-period structures with small energy dissipation, and a simple improvement to match the behaviour was developed for the case studied based on the R-T-m relationship for a range of shaking intensity.

External Conditions, Internal Rationality: Spinoza on the Rationality of Seneca’s Suicide

I argue alongside some other scholars that there is a plausible reading of Spinoza’s philosophy of suicide which holds both of the following tenets: first, that suicides occur because of external conditions, and second, that there are at least some suicides which are rational. These two tenets require special attention because they seem to be the source of significant tension. For Spinoza, if one’s cognitions are to be the most adequate, they must be “disposed internally” (E2p29s/G II 114), or determined more from one’s own mental nature than from “fortuitous encounters” with other things (E2p29s/G II 114). It may seem there is a conflict, then, in saying both that there are rational suicides in the Spinozist framework, and that suicides must always be a result of external conditions: it seems a suicide simply cannot be rational if it is the result of external conditions. But this tension, it will be shown, can be dissolved. Once this tension is dealt with, I offer some brief closing arguments. I explain how this reading of Spinoza’s philosophy of suicide can satisfy a call for new suicide research which avoids forms of over-individualism and epistemic injustice, and which encourages us to abolish oppressive conditions that lead to rational suicides.

Single-Center Experience in Managing Right Liver Grafts From Trifurcation or Independent Right Posterior Portal Vein in Adult Living Donor Liver Transplantation

The right liver graft has sometimes been from the trifurcation portal vein (TPV) or independent right posterior portal vein (IRPPV). Managing these PV anatomies to increase the recipient's survival rate remains challenging. Many published techniques could overcome this problem, such as simple unification venoplasty (SUV), autologous portal Y-graft interposition, conjoined unification venoplasty (CUV) with a baseball-like conduit, and SUV plus circumferential fence-like vein extension. This study reviewed our strategy for managing the right liver grafts from TPV or IRPPV in adult living donor liver transplantation (aLDLT). We enrolled the study population who underwent aLDLT using the grafts with TPV or IRPPV at our institute from October 2004 to October 2022. We analyzed the reconstruction methods for these grafts and postoperative PV complications in donors and recipients. During the study period, of 528 aLDLT recipients, we identified 26 donors with TPV (n=10) or IRPPV (n=16). Eight grafts from TPV had a single PV orifice. The other 18 grafts had dual right PVs that underwent initial PV management, including SUV (n=13), recipient's right and left portal veins to graft's dual PVs (n=2), Y-graft interposition (n=1), CUV (n=1) and SUV with fence-like vein extension (n=1). One SUV graft changed to fence venoplasty due to significant tension for PV anastomosis. The acute right posterior PV thrombus and anterior PV stenosis happened in 2 cases with Y-graft interposition and native PVs direct anastomosis. One donor with TPV had portal vein thrombosis and needed thrombectomy with vein patch repair. The graft from TPV should be carefully planned. A single PV orifice may be feasible but not always possible. An SUV could cover most IRPPVs, but if the distance between the right anterior and posterior PVs is a problem, CUV would be an alternative method. In addition, SUVs with fence venoplasty could relieve PV anastomosis tension.

Toward Accurate Modeling of Galaxy Clustering on Small Scales: Halo Model Extensions and Lingering Tension

This paper represents an effort to provide robust constraints on the galaxy–halo connection and simultaneously test the Planck ΛCDM cosmology using a fully numerical model of small-scale galaxy clustering. We explore two extensions to the standard Halo Occupation Distribution model: assembly bias, whereby halo occupation depends on both halo mass and the larger environment, and velocity bias, whereby galaxy velocities do not perfectly trace the velocity of the dark matter within the halo. Moreover, we incorporate halo mass corrections to account for the impact of baryonic physics on the halo population. We identify an optimal set of clustering measurements to constrain this “decorated” HOD model for both low- and high-luminosity galaxies in SDSS DR7. We find that, for low-luminosity galaxies, a model with both assembly bias and velocity bias provides the best fit to the clustering measurements, with no tension remaining in the fit. In this model, we find evidence for both central and satellite galaxy assembly bias at the 99% and 95% confidence levels, respectively. In addition, we find evidence for satellite galaxy velocity bias at the 99.9% confidence level. For high-luminosity galaxies, we find no evidence for either assembly bias or velocity bias, but our model exhibits significant tension with SDSS measurements. We find that all of these conclusions still stand when we include the effects of baryonic physics on the halo mass function, suggesting that the tension we find for high-luminosity galaxies may be due to a problem with our assumed cosmological model.

Work-life Balance among Work from Home Employees: A Study with Reference to it Companies of Mangalore City

The issue of how to combine work and personal obligations has received more attention in recent years in scholarly and political debates. One programme that has been marketed as a technique to enhance work-life balance is homeworking. This essay looks at the experience of working from home, where a lot of personal tension is typically passed from one partner to the next. The family may experience significant tension and stress when both members work to advance their careers. Couples with kids or other family duties may find this situation to be much more challenging. Since there are more jobs that need computers and telecommunications, more individuals have dependable home Internet connections, and more families have both parents working full-time, the number of people working from home (WFH) has increased. The Covid-19 outbreak hastened this development by compelling a sizable portion of the world's workforce to temporarily convert to WFH. Working from home (WFH) has the ability to promote work-life balance, give more flexible working hours, and cut down on commute time as compared to working from the office (WFO). The more fundamental effects of WFH, such as those on productivity and the elements that influence whether WFH is more or less productive than WFO, are still little understood.

Their Own Best Creations: Women Writers in Postwar Television by Annie Berke

Reviewed by: Their Own Best Creations: Women Writers in Postwar Television by Annie Berke Sara Bakerman (bio) Their Own Best Creations: Women Writers in Postwar Television by Annie Berke. University of California Press. Feminist Media Histories. 2022. 302 pages. $85.00 hardcover; $29.95 paper; also available in e-book. In the summer of 2020, in the midst of a chat about future projects, a senior scholar asked me for recommendations of exemplary studies of individuals in media contexts. As a well-known scholar of the television industry, she wanted to turn her attention to the individuals who created and experienced cultures of production from the inside. Certainly, such studies exist—many of them influence my own work on aging stars—but none came to mind in the moment.1 Today, dear scholar, I'd like to suggest Annie Berke's Their Own Best Creations: Women Writers in Postwar Television as a sterling addition to that category. Berke's book, published in January 2022 by the University of California Press, is notably the first in the new Feminist Media Histories book series edited by Shelley Stamp.2 Like the journal for which that series is named (also founded by Stamp), Their Own Best Creations seamlessly bridges the fields of media studies and feminist studies via a rich and lively exploration [End Page 198] of the women who scripted the first Golden Age of television. In contrast to luminaries such as Lucille Ball and Gracie Allen, most women who worked in the nascent television industry are forgotten today, their names and contributions perhaps briefly acknowledged yet quickly vanishing from the archival register. These neglected talents include Gertrude Berg, writer-star of The Goldbergs (CBS, 1949–1956); Irna Phillips, writer-creator of multiple famed soap operas, including Guiding Light (CBS, 1952–2009) and As the World Turns (CBS, 1956–2010); and Madelyn Pugh, writer of many iconic episodes of I Love Lucy (CBS, 1951–1957). Berke covers their work and that of others in her well-researched history of early television's women writers, whose experience of and perspective on the gender politics of their eras necessarily inform the industry's depiction of them. "The book's title, Their Own Best Creations," Berke writes, "reveals my investment in looking at these women writers' scripted lives, their personas and creative output, as formative presences in postwar femininity."3 The author's interest in these figures reads as neither purely biographical nor simply a righting of media historiography's failure to spotlight such women until now. Instead, Berke shows that women writers—as well as producers, story editors, and analysts—not only understood their place in a burgeoning industry but also experienced, in retrospect, a significant tension between their series' portrayals of postwar sociocultural pressures on gender and femininity and "second-wave feminism's emphasis on professionalism and self-actualization."4 Throughout the book, Berke separates individual subjects from personal politics by drawing comparisons between televisual text and private writings, ultimately crafting an argument that frames each figure through a necessarily feminist lens. Textually and interpersonally, the women who make up Berke's study represent a range of positionalities vis-à-vis gender, politics, and labor. For example, in chapter 3, early domestic sitcoms written by and featuring Berg and Peg Lynch, the writer-star of Ethel & Albert (NBC, CBS, ABC, 1953–1956), are read by Berke as "allegorical plays about women television professionals," a framing that enables their onscreen representation as both "the woman at home and the woman at work, suggesting that smart, motivated women might not have to choose between career and family."5 But Phillips, a trailblazer of soap opera narratives that Berke argues "subtly undermined postwar discourses of sexism and misogyny," rejected the label feminist and did not overtly adhere to such politics in her public persona. Berke references Phillips's obituary notices, which cite the writer's belief that "'women are happier being dependent on men.'"6 Yet, as Berke shows, Phillips's early soaps, situated as they are within the domestic sphere and family life, also demonstrate how the writer "invented herself as someone equipped to express the needs of American women," inventing complex narratives [End Page 199...

Study Investigates Casing Wear in the Culzean Field

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 206221, “Casing Wear: Prediction, Monitoring, Analysis, and Management in the Culzean Field,” by Florian Aichinger, SPE, Loic Brillaud, SPE, and Ben Nobbs, SPE, H&P Technologies, et al. The paper has not been peer reviewed. _ This paper presents predicted vs. measured wear for six wells in the Culzean field, a high-pressure/high-temperature (HP/HT) gas condensate field in the central North Sea. The focus of the complete paper is on the monitoring and analyzing process, particularly how to use offset data to improve accuracy of casing-wear prediction. Field and Well Background Wells in the Culzean field are quite deep, with a measured depth (MD) of 15,000–16,500 ft, and are J-shaped with a slight sail angle (inclination 30–40°). These features result in significant tension loads at the buildup and, potentially, at unplanned curvatures in the vertical section. Combined with possibly high rotating hours, these factors create a considerable risk of high casing wear. Additionally, a challenging pressure regime is present. The steep pressure-transition zone (PTZ) overlying the target reservoir, and the expected predrilled narrow mud-weight window between the pore pressure and formation at the top of the Pentland reservoir of 0.060 ppg, called for a new well-design approach. To address this challenge, the production casing was designed as a 10-in. production liner and a 10¾×10-in. tieback production string. The well design and operations plan required drilling both 12¼- and 8½-in. sections without the 10¾×10-in. tieback production string installed. Consequently, the 14×13⅝-in. intermediate casing could be exposed to higher pressures than usual. Extensive work was performed to enhance casing-wear prediction and to determine the likelihood of failure if a well-control risk materialized. The 12¼-in. section and 10-in. production liner shoe were placed as deeply as possible into the PTZ in the Upper Valhall/Tuxen formation. An appreciable risk was the possibility of a kick while drilling the 12¼-in. section from the Pentland reservoir. The most extreme well-control event the 14×13⅝-in. intermediate casing could experience, however, would have been a well-full-of-gas event while drilling the 8½-in. section. The assessment of the risk associated with such an event was addressed by careful attention to an assessment of casing wear and remaining casing wall thickness and the probability of failure of the 14×13⅝-in. casing, assuming that the casing was worn. The failure-probability assessment of the 14×13⅝-in. intermediate casing was performed using a reliability-based design approach using survival design principles and probability-of-failure estimation. Methodology: Wear Computation and Measurement Analysis of casing wear between a drillstring and the inner surface of casing requires application of an appropriate casing-wear model. A stiff-string model, as used in this work, is advantageous because it can consider pipe clearance, pipe stiffness, and axial and radial casing contact-point location. The simulation uses an adaptable 3D mesh, allowing the calculation of wear in all radial orientations for every chosen MD. The multifinger-caliper-log (MFCL) interpretation methodology uses inner-diameter measurements to calculate an ellipse that best fits the casing shape. The methodology does not require a base log and increases accuracy compared with the traditional method of comparing the maximum inner diameter of MFCL logs taken before and after drilling. The methodology also can be applied to sonic logs as a second information source apart from the direct wall-thickness measurement if the latter is not available. A detailed overview of this process is included in the complete paper.

Variant Plateau’s law in atomically thin transition metal dichalcogenide dome networks

Since its fundamental inception from soap bubbles, Plateau’s law has sparked extensive research in equilibrated states. However, most studies primarily relied on liquids, foams or cellular structures, whereas its applicability has yet to be explored in nano-scale solid films. Here, we observed a variant Plateau’s law in networks of atomically thin domes made of solid two-dimensional (2D) transition metal dichalcogenides (TMDs). Discrete layer-dependent van der Waals (vdWs) interaction energies were experimentally and theoretically obtained for domes protruding in different TMD layers. Significant surface tension differences from layer-dependent vdWs interaction energies manifest in a variant of this fundamental law. The equivalent surface tension ranges from 2.4 to 3.6 N/m, around two orders of magnitude greater than conventional liquid films, enabling domes to sustain high gas pressure and exist in a fundamentally variant nature for several years. Our findings pave the way towards exploring variant discretised states with applications in opto-electro-mechanical devices.

Study of Application of Fiber Reinforced Concrete in Anchorage Zone

In the case of post-tensioned or geotechnical structures, the anchorage zone is considered a critical part of the design and construction process. Generally, the failure of the anchorage zone is one of the most common problems. High-bearing stresses create significant transverse tension. For these reasons, conventional reinforcement, usually in the form of closed stirrups, must be designed. The presented analysis is focused on the possible increase of load-carrying capacity of the anchorage zone with steel fiber-reinforced concrete. Three types of specimens were analyzed. The first type of specimen represented the anchorage zone made from standard reinforced concrete. The second and third series of specimens were designed from fiber-reinforced concrete with two different volumes of steel fibers added into the anchorage zone. The parameters used in the numerical analysis of the anchorage zone were experimentally determined on a set of beam specimens. In the analysis, the anchorage zone was loaded by a node force applied on a steel load distribution plate placed on the top edge of the bloc. The performed numerical study suggests that the load-bearing capacity can be increased by adding fiber-reinforced concrete with a higher volume of fiber (Dramix 3D 55/30, volume of fiber of 110 kg/m3) into the vicinity of the anchorage plate.

Elbow Soft Tissue Coverage after Trauma

Traumatic injuries involving the elbow can result in soft tissue defects with exposed critical structures including bone, joint, nerve, tendons or implants.1 Additionally, wounds about the elbow are subject to significant motion and tension, limiting the success of local wound care.2 In these clinical settings, soft tissue reconstruction is often indicated. The goal of reconstruction is elbow wound coverage with pliable, thin, and durable tissue that allows for repetitive motion without limiting range of motion.3 In the post-traumatic setting, optimal function is achieved if the soft tissue reconstruction allows for early return to active motion of the elbow joint.4

The laser surface treatment effective on Mechanical properties Cerment compounds(Al2O3+Ni-Al)

This work investigates the using thermal spray coating by Flame as a method to produce high performance cerment coating. In this study , an alumina was added to the self bounding of Ni- Al .This cerment composite materials sprayed through aflame towards a graphite substrate . The aim of the work is to see the effective of laser treatment on the microstructural of the coating layers . The results show that coating consists of different morphology zones surface defects and pores . The laser analysis predicts that remelted all surface particles with a significant high surface tension , producing strongly hardness with improvement in the structurel and mechanical properties.

A Feasible Technique for Transoral Endoscopic Thyroidectomy Through Vestibular Access Using a Single-port Technique: A Video Vignette in Cadaver Dissection

The aim of this study was to evaluate the safety and feasibility of a single-port system for transoral endoscopic thyroidectomy with vestibular access (TOETVA). Two embalmed human cadavers were used to test the single-port technique. After positioning, a median vestibular incision was made. Adipose tissue was dissected through the mentum with a Kelly clamp to reach the subplatysmal level. The Keyport Single Port System (Richard Wolf) was then inserted. After port placement, flexible endoscopic dissectors and a 5-mm endoscope were advanced. After removing the dissectors, we inserted the ArtiSential laparoscopic instruments. We also used a 3-port TOETVA on another human cadaver to compare the results with those of the single-port surgery. In the first cadaver, skin tension was observed during trocar insertion and dissection. Trocar insertion resulted in skin perforation in the submental area. In the second cadaver, the single-port trocar was successfully inserted despite the significant skin tension. However, the trocar did not allow the necessary surgical maneuvers to proceed with subsequent surgical steps and create a working space. Postprocedural anatomic dissection revealed that the distal branches of the mental nerve were related to the trocar passage. Our cadaver study demonstrated that single-port TOETVA is unsafe and not feasible with the current technology of the Keyport single-port system. This approach needs to be improved to perform this technique without injury to distal branches of the mental nerve, skin perforation, and other complications.

Shifting paradigms in stormwater management – hydrosocial relations and stormwater hydrocitizenship

ABSTRACT Stormwater management has recently begun a paradigm shift away from traditional top-down approaches in response to climatic changes, urbanization, and regulatory pressures. This paradigm shift is characterized by two key developments: the implementation of additional decentralized green infrastructure, and the practice of individuals managing stormwater from their privately-owned property. This transition involves redefining who is responsible for managing stormwater and the infrastructure used within stormwater management. Using insights from two urban watersheds, Watershed 263, Baltimore, MD and Watts Branch, Prince George’s County, MD and Washington, DC, where this shift is underway, we assess changes in the hydrosocial relationships underpinning this paradigm shift including the emergence of stormwater hydrocitizenship. We investigate stormwater hydrocitizenship as the role and responsibilities of individuals within stormwater management. We focus on the role of government at several levels, drawing insights from the concept of biopower. Our findings suggest that this paradigm shift and the emergence of a stormwater hydrocitizenship remains embedded in top-down governance, which in turn creates significant tension among different stakeholders. Arising from this critical analysis, we seek to promote a reimagining of how, where, and who manages stormwater towards more sustainable, resilient, and equitable outcomes.

Pore-scale modelling on hydrogen transport in porous media: Implications for hydrogen storage in saline aquifers

Hydrogen energy has tremendous potential as a clean fuel in this energy transition. To build up the full-scale hydrogen energy supply chain, large-scale hydrogen storage is of vital importance. Underground hydrogen storage in saline aquifers has been perceived as an important means to achieve large-scale hydrogen storage. Therefore, we investigated hydrogen transport in pore network in a sandstone porous media at strongly water-wet and weakly water-wet (hydrogen-wet). We performed direct numerical simulation through volume of fluid method to investigate the transport of hydrogen at pore-scale under different wetting conditions with input hydrogen-rock physics data from literature. Our results showed that during primary drainage process (hydrogen injection for storage purpose), increasing hydrogen wetting decreased snap-off effect, enabling a greater pore space for hydrogen storage. During primary imbibition process (hydrogen extraction), increasing hydrogen wetting promoted the size and stability of hydrogen clusters, which is unfavorable to hydrogen extraction process. Given the significant high interfacial tension between brine and hydrogen and low viscous force of hydrogen, snap-off effect dominates the flow in both hydrogen injection and extraction process regardless of wetting conditions. This physical process causes the recovery factor even below 20%. We therefore suggest that storing hydrogen in depleted gas reservoirs under irreducible water saturation would have much less risks in hydrogen trapping during extraction process.

Online communication strategy of world political leaders during the Ukraine crisis (February 24 - December 24, 2022). Comparative case study: Joe Biden, Ursula von der Leyen and Jens Stoltenberg

This case study looks at the online communication strategies of three prominent world political leaders during the Ukraine crisis in February-December 2022. Using the case studies of U.S. President Joe Biden, European Commission President Ursula von der Leyen, and NATO Secretary General Jens Stoltenberg, this study examines how the three leaders used online communication tools to shape their respective strategies and communicate their messages to the international community. Through an in-depth analysis of each leader's approach to online communication, the study reveals how the three leaders used varying levels of engagement, commentary, and content to project strength, unity, and stability during a time of significant international tension. It also highlights how each leader used different strategies to reach and engage a global audience, indicating a clear need to understand the nuances of online communication to successfully navigate complex global crises. The study ultimately suggests that strategic use of online communication can be a powerful tool for world leaders in times of international crisis.