bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomass-derived cobalt/carbon hierarchically structured composites for efficient oxygen electrocatalysis and zinc–air batteries
Authors: Chen Jing , Yang Shaoxuan , Zhang Zhengping , Wang Feng
Published: June 2022

In this work, we constructed a biomass-derived composite (denoted as Co@Co–N,S–C), which exhibited excellent efficient bifunctional performance for ORR/OER, as well as an outstanding performance when employed in secondary zinc–air batteries.
Molecular mechanisms of the antibacterial activity of polyimide fibers in a skin-wound model with Gram-positive and Gram-negative bacterial infection in vivo
Authors: Yang Xia , Ma Wei , Lin Hua , Ao Shengxiang , Liu Haoru , Zhang Hao , Tang Wanqi , Xiao Hongyan , Wang Fangjie , Zhu Junyu , Liu Daoyan , Lin Shujun , Zhang Ying , Zhou Zhongfu , Chen Changbin , Liang Huaping
Published: June 2022

A novel natural polyimide fiber was identified and displayed significant antibacterial activity against E. coli and MRSA in vitro and in vivo, may act as a promising candidate for antimicrobial material for trauma and surgical applications.
Application of reduced graphene oxide as the hole transport layer in organic solar cells synthesized from waste dry cells using the electrochemical exfoliation method
Authors: Negash Asfaw , Demeku Aknachew M. , Molloro Liboro Hundito
Published: June 2022

The hole transport layer (HTL) plays an important role in improving the efficiency and stability of organic solar cells (OSCs).
Review of electrical stimulus methods ofin situtransmission electron microscope to study resistive random access memory
Authors: Zhang Yewei , Wang Chaolun , Wu Xing
Published: June 2022

This review introduces thein situelectrical transmission electron microscope technologies that apply various electrical stimuli to resistive random access memory (RRAM) devices exploring the microscopic process of RRAM in different working modes.
Synthesis of degradable double network gels using a hydrolysable cross-linker
Authors: Yokoi Takanori , Kuzuya Akinori , Nakajima Tasuku , Kurokawa Takayuki , Gong Jian Ping , Ohya Yuichi
Published: June 2022

Biodegradable double network (DN) gels with remarkably high mechanical strength and toughness were synthesised. The biodegradable DN gels can be potentially applied in biomedical applications such as cartilage regeneration.
Alkene insertion reactivity of a o-carboranyl-substituted 9-borafluorene
Authors: Bischof Tobias , Guo Xueying , Krummenacher Ivo , Beßler Lukas , Lin Zhenyang , Finze Maik , Braunschweig Holger
Published: June 2022

A 9-carboranyl-substituted 9-borafluorene is reported, which is capable of undergoing efficient ring expansion to 6,7-dihydroborepins by a previously unknown alkene insertion.
MXene in core–shell structures: research progress and future prospects
Authors: Lamiel Charmaine , Hussain Iftikhar , Ogunsakin Olakunle Richard , Zhang Kaili
Published: June 2022

MXene is an emerging two-dimensional (2D) material whose properties have been well-evaluated to cater to a wide range of applications.
Synergetic catalysis of p–d hybridized single-atom catalysts: first-principles investigations
Authors: Deng Meng , Xia Mengjiao , Wang Yueyang , Ren Xiaoyan , Li Shunfang
Published: June 2022

2D-TM3(C6O6)2 systems are predicted to be effective p–d hybridized catalysts for CO oxidization via the synergetic interplay of charge transfer among the hosting d-block TM active sites, the neighboring p-block C and O atoms in the substrate.
A2Zn3P4S13 (A = Rb and Cs): First Infrared Nonlinear Optical Materials with Mixed Thiophosphate Functional Motifs PS4 and P2S6
Authors: Li Ming-Ze , Jiang Lin-Tao , Pei Shao-Min , Liu Bin-Wen , Jiang Xiao-Ming , Guo Guo-Cong
Published: June 2022

Two new IR NLO thiophosphates A2Zn3P4S13 (A = Rb, Cs) feature [Zn3P4S13] anionic framework and contain two types of NLO-active thiophosphate units (PS4 and P2S6), which to our best knowledge is unprecedented in known IR NLO thiophosphates.
Resource allocation for IRS‐assisted MC MISO‐NOMA system
Authors: Javadi Sepideh , Shafiei Hossein , Forouzanmehr Malihe , Khalili Ata , Nguyen Ha H.
Published: June 2022

In this paper, a downlink multi‐user communication of an intelligent reflecting surface (IRS)‐assisted multiple‐input single‐output (MISO) power‐domain non‐orthogonal multiple access (NOMA) system is investigated. Considering multi‐carrier (MC) transmission and to enhance user fairness, two users are assigned to the same subcarrier. For such a system, the authors optimize active beamforming at the base station (BS), subcarrier allocation policy, and phase shifts at the IRS to maximize the system throughput. A semi‐definite relaxation (SDR) is applied to tackle the non‐convex optimization problem, and an alternating optimization (AO) algorithm is proposed to obtain a suboptimal solution. Numerical results illustrate the higher throughput of the proposed MC multi‐user IRS‐aided MISO‐NOMA system as compared to the conventional IRS‐assisted orthogonal multiple access (OMA) system.
A time latch for high speed time‐based ADCs
Authors: Abdelaziz Ahmed , Musah Tawfiq
Published: June 2022

This letter presents a novel time latch for high speed time domain analogue to digital converters. The time latches reported in literature suffer from a limited maximum operating frequency, which makes them unsuitable for high frequency applications. Analysis of the proposed time latch shows it can operate at 10 GHz, 2.5x higher than the best reported time latch. Furthermore, simulations in 28 nm CMOS technology confirm that the enhancement in the speed of the proposed time latch comes with low overhead in area and power. Potential design issues with the proposed time latch are also discussed.
Photonic‐assisted one‐third microwave frequency divider
Authors: Zhang Yu , Zheng Ruiqi , Chan Erwin Hoi Wing , Wang Xudong , Feng Xinhuan , Guan Bai‐Ou , Yao Jianping
Published: June 2022

A microwave photonic frequency divider to produce a frequency‐divided microwave signal with its frequency that is one‐third the frequency of the input microwave signal is proposed and experimentally demonstrated. The key novelty of the approach is that the phase control, a condition to realise the frequency division operation, is implemented through controlling the modulator bias voltage, enabling a wideband, high resolution and fast response phase control. One‐third frequency division with an ultra‐high harmonic suppression of over 71.5 dB is demonstrated for the first time.
Fairness concern‐based coordinated vehicle route guidance using an asymmetrical congestion game
Authors: Zhang Le , Khalgui Mohamed , Li Zhiwu , Zhang Yongsheng
Published: June 2022

In this paper, an asymmetrical congestion game is used to build a fairness concern‐based coordinated route guidance model for alleviating traffic congestion. Coordinated vehicle route guidance is commonly recognized as an effective way to alleviate the “route flapping” phenomenon, where a new congestion appears since numerous vehicles obey the same guidance in selfish route diversion. The existing studies mainly use the classic (symmetrical) congestion games, whose payoff depends only on the number of chosen players, to calculate the flow proportion for the alternative roads. This mechanism may make some front vehicles receive the worse payoffs than the rear ones, which further results in the front vehicles being unwilling to execute the recommended paths due to their unfair psychology. Players' fairness concern in game theory has been noted in some fields (such as supply chain) but not traffic route guidance. In this work, to fill the above gap, the concept of vehicular fairness concern is introduced and the corresponding mathematical expression is formulated. An asymmetrical congestion game‐based coordination route model is built, which can improve the fairness coefficient of vehicles. Moreover, a reinforcement learning‐based approximated solving algorithm is designed since the existing solving theorems are not necessarily valid for the asymmetrical congestion game. An experimental study shows that (1) the Nash equilibrium coefficients generated by the approximated solving algorithm all converge to 1.00, and (2) the averaged fairness coefficient is increased from 0.92 to 0.96 on the basis of equal travel time due to the improved payoff functions.
Licht im Paragrafendschungel
Authors: Nock Hermine
Published: June 2022

Eltern von herzkranken Kindern fühlen sich oft wie in einem Dschungel aus Bestimmungen und Möglichkeiten, in dem es schwierig ist, den Durchblick zu behalten. Der Bundesverband Herzkranke Kinder e. V. bietet mit seiner Sozialrechtshotline Unterstützung und Hilfe.
Schulgesundheitspflege ist auch ein Auftrag der Sorge und Zuwendung
Authors: Kocks Andreas
Published: June 2022

Wer bei Schulgesundheitspflege nur daran denkt, Pflaster auf verletzte Knie zu kleben oder Splitter aus Fingern zu ziehen, unterschätzt die Aufgaben der Pflegenden gewaltig. Sie sind vielmehr Anlaufstelle für alle Sorgen und Nöte der Schüler und bieten so nicht nur physische, sondern auch wertvolle psychische Unterstützung.
Visible-Light-Mediated Direct Amidation of Arenes and Hetero­arenes with N-Aminopyridinium Salts
Authors: Li Yaming , Xia Cencen , Hao Xinyu , Jin Kun , Zhang Rong , Duan Chunying
Published: June 2022

A novel photoinduced strategy has been developed for the C–H amidation of aromatics and heteroaromatics by using benzamide radicals with free NH groups generated from N-amidopyridinium salts under visible-light irradiation. The new mode of activation of N-amidopyridinium salts proceeds efficiently under mild conditions to give various benzamide derivatives with free NH groups. In addition, oxazoline analogues, synthesized by the reaction with styrene, demonstrate a substantial range of prospective applications for this versatile protocol.
Use of Vinyl Sulfides in Fischer Indole Reactions
Authors: Pal Parul , Fragis Meghan , Magolan Jakob , Dharavath Srinivas , Johnson Jarrod W.
Published: June 2022

Vinyl sulfides accessed via Wittig olefination with thioalkylphosphonium salts are used as aldehyde- or ketone surrogates in Fischer indole reactions. These vinyl sulfides react with arylhydrazines in the presence of TsOH·H2O in refluxing ethanol or dichloroethane to yield diverse 3-substituted and 2,3-disubstituted indoles or azaindoles. The utility of this chemistry is highlighted with the efficient preparation of three biomedically relevant compounds: 4-aza-melatonin, a furoindoline, and an indomethacin-like CRTh2 antagonist.
Postoperative Musculoskeletal Imaging and Interventions Following Hip Preservation Surgery, Deformity Correction, and Hip Arthroplasty
Authors: Samim Mohammad , Khodarahmi Iman , Burke Christopher , Fritz Jan
Published: June 2022

Total hip arthroplasty and hip preservation surgeries have substantially increased over the past few decades. Musculoskeletal imaging and interventions are cornerstones of comprehensive postoperative care and surveillance in patients undergoing established and more recently introduced hip surgeries. Hence the radiologist's role continues to evolve and expand. A strong understanding of hip joint anatomy and biomechanics, surgical procedures, expected normal postoperative imaging appearances, and postoperative complications ensures accurate imaging interpretation, intervention, and optimal patient care. This article presents surgical principles and procedural details pertinent to postoperative imaging evaluation strategies after common hip surgeries, such as radiography, ultrasonography, computed tomography, and magnetic resonance imaging. We review and illustrate the expected postoperative imaging appearances and complications following chondrolabral repair, acetabuloplasty, osteochondroplasty, periacetabular osteotomy, realigning and derotational femoral osteotomies, and hip arthroplasty.
Towards Equitable and Resilient Digital Primary Care Systems: An International Comparison and Insight for Moving Forward
Authors: Kuziemsky Craig , Liaw Siaw-Teng , Leston Meredith , Pearce Christopher , Jonnagaddala Jitendra , de Lusignan Simon
Published: June 2022

Objective: While the COVID-19 pandemic provided a global stimulus for digital health capacity, its development has often been inequitable, short-term in planning, and lacking in health system coherence. Inclusive digital health and the development of resilient health systems are broad outcomes that require a systematic approach to achieving them. This paper from the IMIA Primary Care Informatics Working Group (WG) provides necessary first steps for the design of a digital primary care system that can support system equity and resilience.

Methods: We report on digital capability and growth in maturity in four key areas: (1) Vaccination/Prevention, (2) Disease management, (3) Surveillance, and (4) Pandemic preparedness for Australia, Canada, and the United Kingdom (data from England). Our comparison looks at seasonal influenza management prior to COVID-19 (2019-20) compared to COVID-19 (winter 2020 onwards).

Results: All three countries showed growth in digital maturity from the 2019-20 management of influenza to the 2020-21 year and the management of the COVID-19 pandemic. However, the degree of progress was sporadic and uneven and has led to issues of system inequity across populations.

Conclusion: The opportunity to use the lessons learned from COVID-19 should not be wasted. A digital health infrastructure is not enough on its own to drive health system transformation and to achieve desired outcomes such as system equity and resilience. We must define specific measures to track the growth of digital maturity, including standardized and fit-for-context data that is shared accurately across the health and socioeconomic sectors.
Evaluation of Stress Distribution in Implant Body and Surrounding Bone with and without Splinting—A Three-Dimensional Finite Element Analysis: An In Vitro Study
Authors: Wahengbam Prashanti , Kalra Tarun , Kumar Manjit , Bansal Ajay
Published: June 2022

Introduction This study was undertaken to evaluate the pattern of stress distribution in implant body and surrounding bone with and without splinting of implant prostheses when subjected to occlusal loading, using the finite element analysis.

Methods The geometric models of implant and mandibular bone were generated. Two models were created in accordance with the need of the study. The first model was given a two implant in the first mandibular molar and second premolar with splinted prosthesis. Then, second model was given two such implants in the same region but without splinting the prosthesis. Forces of 100 N and 50 N were applied axially and buccolingually, respectively.

Results The maximum von Mises stress values with axial force of the implant splinted prosthesis were observed to be 4.21 MPa for cortical bone, 0.88 MPa for cancellous bone, and 10.592 MPa for implant body. The maximum von Mises stress values with buccolingual force of the implant splinted prosthesis were observed to be 9.08 MPa for cortical bone, 1.33 MPa for cancellous bone, and 30.08 MPa for implant body. The maximum von Mises stress values with axial force of the implant nonsplinted prosthesis were observed to be 4.51 MPa for cortical bone, 0.91 MPa for cancellous bone, 13.18 MPa for implant body. The maximum von Mises stress values with buccolingual force of the implant nonsplinted prosthesis were observed to be 9.52 MPa for cortical bone, 1.91 MPa for cancellous bone, 35.04 MPa for implant body.

Conclusion The maximum stresses were transferred more to the implant body than to the bone in both the splinted and nonsplinted implant prostheses. The maximum von Mises stresses were observed on nonsplinted implant prostheses, so splinting implant prostheses led to lower stress in the implant body and surrounding bone.
Postoperative Ankle Imaging, 2022
Authors: Shrestha Roman , Sill Andrew P. , Haug Logan P. , Patel Karan A. , Kile Todd A. , Fox Michael G.
Published: June 2022

Postoperative ankle imaging requires knowledge of the underlying surgical techniques, the usefulness of various imaging modalities, as well as an appreciation for the desired clinical outcomes. Surgical procedures discussed in this article are tibiotalar fracture fixation, tibiotalar, subtalar, and tibiotalocalcaneal arthrodesis, total ankle arthroplasty, talar osteochondral lesion repair and grafting, lateral ligamentous repair and reconstruction, and peroneal and Achilles tendon repair and reconstruction. Imaging can play a vital role in determining if the expected outcome has been achieved and identifying complications, with particular emphasis placed on the use of radiographs, computed tomography (including weight-bearing), magnetic resonance imaging, and ultrasonography.
A diagnostic tool for family and marriage counseling with Muslim couples
Authors: Soliman Abdrabo , Abdel-Salam Abdel-Salam G. , Ahmed Mervat
Published: June 2022

This study aimed to describe the development and psychometric properties of a questionnaire for Muslim couples and families based on how couples view and experience marital and family issues. A questionnaire was developed based on relevant literature and fine-tuned by a panel of experts. The questionnaire was administered to a sample of 1212 heterosexual Muslim individuals of 389 married couples aged 22–55 years old (overall mean age = 38.15 years, SD = 9.47; husbands’ mean age = 38.25 years, SD = 9.23; wives’ mean age = 38.06, SD = 9.70). The participants were divided into two subsamples for exploratory and confirmatory factor analysis and to draw Pearson correlations with the Dyadic Adjustment Scale (DAS) for validation procedures. The results indicate the strong statistical significance of a 22-item five-factor structure: structural attribute satisfaction, marital harmony, emotional and sexual harmony, spouse’s family communication, and religious matters. The factors were interpreted theoretically and indicate a superior level of internal consistency. The validation process indicates that the questionnaire was appropriate for the targeted population. The validated tool is useful for the assessment of marital and family therapy with Muslim couples and families. The WIFAQ Questionnaire for Muslim Couples and Families (WQMCF) fills a critical gap in the market for a family health indicator that can be used in both local and national populations. In health care settings and organizations that provide services to families, the WQMCF may be an important screener of family and marriage counseling in Muslim couples. Individuals, communities, and nations can all benefit from a stronger understanding of the antecedents and outcomes of family health.
Particle-in-cell modeling of plasma jet merging in the large-Hall-parameter regime
Authors: Wen H. , Ren C. , Hansen E. C. , Michta D. , Zhang Y. , Langendorf S. , Tzeferacos P.
Published: June 2022

The merging process of magnetized plasma jets with parameters relevant to the plasma-jet-driven magneto-inertial fusion (PJMIF) design and the plasma liner experiment (PLX) is modeled by fully kinetic particle-in-cell (PIC) simulations in one and two spatial dimensions. The modified two-stream instability is identified to be the main mechanism responsible for stopping the plasma jets and preventing species interpenetration. The electron and ion Hall parameters of the merged plasma are greater than unity, and the plasma β is close to unity, which is the desired characteristic of planned experiments at PLX. Our 2D PIC simulations validate the results of the radiation magneto-hydrodynamics code FLASH, which will be the primary tool for modeling various stages of future PJMIF experiments.
Trap passivation in perovskite films for improved electrical properties and charge dynamics
Authors: Liu Xiangyang , Liu Xinsheng , Cui Yunkang , Sun Leshuai , Qin Chaoran , Wang Yiran , Liang Miao
Published: June 2022

Perovskite films modified by a polymer will largely enhance the open circuit voltage (VOC) and cannot increase the short-circuit current (JSC) and fill factor (FF). In order to further optimize perovskite films, an ionic conducting polymer containing diblock-polymers of polyethylene oxide (PEO)150–polyphenylene oxide (PPO)30 and alkali metal salts of KBr was incorporated into perovskite films. The hydrophilic PEO blocks will coordinate with polar cations and form uniform heterostructure interfaces to passivate defects at grain boundaries (GBs). The transport of alkali metal ions in polymers will increase the conductivity of perovskite films. The synergistic effects of polymers and KBr can significantly enhance the photovoltaic response. The entirely functionalized perovskite GBs can also improve the tolerance of perovskite films against environmental stress. Aside from that, the glycine solution was deposited onto SnO2 films to passivate interface defects and further improve device performance. The improved charge transport dynamics and the suppressed charge recombination kinetics were determined using different characterization techniques. The optimized photoelectric conversion efficiency is 22.89% (a VOC of 1.166 V, a JSC of 24.30 mA cm−2, and a FF of 0.808) under a reverse scan. This work provides a feasible method to further optimize perovskite films and improve device performance.
Analysis of the sharpening effect in gyromagnetic nonlinear transmission lines using the unidimensional form of the Landau–Lifshitz–Gilbert equation
Authors: Greco Ana F. G. , Rossi José O. , Barroso Joaquim J. , Yamasaki Fernanda S. , Teixeira André F. , Rangel Elizete G. L. , Neto Lauro P. S. , Schamiloglu Edl
Published: June 2022

Continuous nonlinear transmission lines (NLTLs), also known as gyromagnetic lines, consist of ferrite-based magnetic cores biased by an external magnetic field. Over the past years, many analytical and experimental studies have predicted the rise time reduction of the input pulse to the range of a few nanoseconds or even hundreds of ps experimentally observed in such gyromagnetic lines. This effect, known as pulse sharpening, is investigated in this paper built on a model based on a periodic structure of inductive–capacitive cells in series with magnetization-driven voltage sources expressed by the one-dimensional form (1D) of the Landau–Lifshitz–Gilbert (LLG) gyromagnetic equation. We explore the model through parametric study under various input–pulse parameters to understand the physics behind the ferrimagnetic material responses. Moreover, the numerical results obtained from computational simulations using Mathematica (v. 12.1) show how the line parameters (input voltage, damping constant, saturation magnetization, and length) affect the sharpening effect, which is quantified by the switching time. Our results on ferrite-loaded coaxial lines have confirmed many results found in the literature. We validated with a good agreement the proposed model with the result obtained by Dolan in 1993 using the same 1D form of the LLG equation, thus showing that the model proposed here is suitable to quantify the sharpening effect produced by a gyromagnetic NLTL.
Collisional ionization and recombination effects on coalescence instability in chromospheric partially ionized plasmas
Authors: Murtas Giulia , Hillier Andrew , Snow Ben
Published: June 2022

Plasmoid-mediated fast magnetic reconnection plays a fundamental role in driving explosive dynamics and heating, but relatively little is known about how it develops in partially ionized plasmas (PIP) of the solar chromosphere. Partial ionization might largely alter the dynamics of the coalescence instability, which promotes fast reconnection and forms a turbulent reconnecting current sheet through plasmoid interaction, but it is still unclear to what extent PIP effects influence this process. We investigate the role of collisional ionization and recombination in the development of plasmoid coalescence in PIP through 2.5D simulations of a two-fluid model. The aim is to understand whether these two-fluid coupling processes play a role in accelerating reconnection. We find that, in general, the ionization–recombination process slows down the coalescence. Unlike the previous models in Murtas et al. [Phys. Plasmas 28, 032901 (2021)] that included thermal collisions only, ionization and recombination stabilize current sheets and suppress non-linear dynamics, with turbulent reconnection occurring in limited cases: bursts of ionization lead to the formation of thicker current sheets, even when radiative losses are included to cool the system. Therefore, the coalescence timescale is very sensitive to ionization–recombination processes. However, reconnection in PIP is still faster than in a fully ionized plasma environment having the same bulk density: the PIP reconnection rate (MIRIP=0.057) increases by a factor of ∼1.2 with respect to the MHD reconnection rate (MMHD=0.047).
Beyond T-graphene: Two-dimensional tetragonal allotropes and their potential applications
Authors: Ghosal Supriya , Jana Debnarayan
Published: June 2022

Breakthrough of graphene dictates that decreasing dimensionality of the semiconducting materials can generate unusual electronic structures, excellent mechanical, and thermal characteristics with remarkable stability. Silicene, germanene, and stanene are the next 2D stable counterparts of other elements belonging to the same group. Since these monolayers possess hexagonal symmetry, scientists had already explored the possibility in the post graphene era of whether hexagonal symmetry was the main and utmost criterion for achieving Dirac cone. This motivation gave birth to T-graphene, a tetragonal network comprised of carbon atoms. However, T-graphene is not the only candidate for exhibiting Dirac fermion. In recent days, tetragonal monolayers of Si and Ge, i.e., T-Si and T-Ge, have been predicted to be stable. These 2D tetragonal allotropes remarkably possess double Dirac cones in their electronic band structure. As these monolayers possess buckling similar to silicene and germanene, the electronic bandgap can be easily introduced in the presence of an external electric field. Another technique to open bandgap is to apply strain in hydrogenated tetragonal networks. Tunable electronic properties in these tetragonal systems make them efficient for optoelectronics as well as thermoelectric applications. Moreover, due to delocalized π electrons, quantum dot systems comprised of tetragonal Si and Ge network show remarkable characteristics in the field of nonlinear optics. Recently, based on theoretical calculations, a bilayer T-graphene system is predicted with excellent mechanical strength relative to its monolayer variant. Not only group-IVA, group-VA elements also exhibit stable monolayer structures. Rather than T-graphene, T-Si, and T-Ge, these monolayers, however, possess intrinsic semiconducting properties, which enable them as a potential candidate for optoelectronic applications. Furthermore, several possible routes have been introduced to realize these systems experimentally. In this topical Review, we would critically explore the recent advancements of 2D tetragonal networks containing group-IVA and VA elements and their possible application perspectives in the field of thermoelectrics and nano-photonics.
Screening effects in dense Coulomb media: Beyond the Poisson–Boltzmann and Kirkwood approximations
Authors: Bondarev V. N. , Dragan G. S.
Published: June 2022

A theoretical approach is proposed that allows giving a suitable description of the equilibrium characteristics of dense heterogeneous Coulomb media, for example, dusty plasma (DP) and ionic colloidal suspensions containing charged particles (grains) of finite size. It is shown that taking into account the Carnahan–Starling closed formula for the contribution of hard spheres of diameter d and number density n into the free energy of DP essentially improves the approximations by Poisson–Boltzmann (ideal gas of point ions) and Kirkwood (ideal gas of finite-sized ions). Thus, in systems like DP, along with the Kirkwood parameter (the ratio of d to the Debye–Hückel screening length), a second independent dimensionless parameter nd3 appears. As a result, for the first time, an opportunity opens up to give a natural explanation of the experimental fact, according to which the screening length in a concentrated electrolyte may turn out to be an increasing function of nd3. Useful evidence of the internal consistency of the theory is that it allows one to give a satisfactory numerical estimate of the dimensionless temperature of DP triple point (vapor–liquid–solid), in agreement with Monte Carlo simulations for concentrated electrolytes like CsCl. Furthermore, the results obtained are in quantitative agreement with a fairly wide set of experimental data on the melting of real ionic crystals (from LiF to CsI and from MgO to BaO) and, thus, provide a theoretical basis for the long-established empirical “similarity rule” that relates melting temperatures to effective ion sizes.
Ab initio simulations of metal contacts for graphene-based devices
Authors: Qin Hancheng , Lu Wenchang , Bernholc J.
Published: June 2022

The precise atomic structure of a metal contact significantly affects the performance of nanoscale electronic devices. We use an accurate, DFT-based non-equilibrium Green’s function method to evaluate various metal contacts with graphene or graphene nanoribbons. For surface metal contacts not chemically bound to graphene, Ti contacts have lower resistance than those of Au, Ca, Ir, Pt, and Sr. However, as an edge contact, Ti has larger resistance than Au. Bridging O atoms at Ti and Au edge contacts lowers the transmission by over 30%.
Modeling submerged granular flow across multiple regimes using the Eulerian–Eulerian approach with shear-induced volumetric behavior
Authors: Phan Quoc T. , Bui Ha H. , Nguyen Giang D.
Published: June 2022

The behavior of submerged granular flow is strongly dependent on the solid volume fraction and the viscosity discontinuity over a wide range of flow regimes. To obtain a general description of this type of flow, this study proposes a new model to compute solid effective stresses of submerged granular materials across multiple flow regimes. Here, based on the critical state soil mechanics framework, a new equation is proposed to describe the evolution of elastic reference of materials caused by elastoplastic deformation. The evolution of elastic reference subsequently informs the development of static pressure, and together with the dynamic pressure computed using a well-established blended model, resulting in a new approach to compute the solid pressure induced by both dynamic and static effects. The proposed model is then implemented in the Eulerian–Eulerian approach using the finite volume method to simulate the collapses of submerged granular columns, covering different flow regimes from quasi-static to viscous depositions. Simulation results agreeing well with experimental and numerical data in the literature are a testament to the performance of a well-developed constitutive law. In addition, the simulation results comprehensibly demonstrate the important role of interstitial fluid flow as well as the initial solid volume fraction in the collapsing process across different flow regimes with different packing densities. Furthermore, the effects of initial volume fraction, fluid pressure, and phase interaction forces on the flow responses are also discussed.
An oversized Ku-band Cerenkov oscillator with pure TM01 mode output
Authors: Fan Zhiqiang , Sun Jun , Cao Yibing , Wu Ping , Song Zhimin , Hou Ruidong , Shi Yanchao , Li Shuang
Published: June 2022

An oversized Ku-band Cerenkov oscillator with pure TM01 mode output is proposed. By utilizing a separated slow-wave structure (SSWS), the resonant characteristic of the operating mode is preserved, whereas the resonant characteristics of the high order electromagnetic modes are destroyed. As a result, only the expected mode can be stimulated, and undesired beam–wave interactions are suppressed effectively. In terms of an oversized Cerenkov oscillator, the usage of SSWS shows great potential for obtaining pure operating mode output. By utilizing particle-in-cell simulation, microwaves with an output power of 4.5 GW and frequency of 14.1 GHz are obtained, when the beam voltage is 0.9 MeV, and the beam current is 12.9 kA. The percentage of the operating mode is up to 99.5% and exceeds 99% in a wide range of the beam voltage.
Ab initio determination of interfacial thermal conductance for polymer-bonded explosive interfaces
Authors: Fan Hang , Zhang Kun , He Guansong , Yang Zhijian , Nie Fude
Published: June 2022

Understanding the thermal transport in polymer-bonded explosives (PBXs) is critical for enhancing the safety and reliability during PBX design, especially in the absence of effective experimental measurements. In this work, we rigorously investigated the phonon properties of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and polyvinylidene fluoride (PVDF) and calculated the interfacial thermal conductance using an ab initio approach. The diffuse mismatch model and anharmonic inelastic model were adopted to examine the interfacial thermal conductance as a function of temperature for the TATB–PVDF interface. Our calculation results indicate that low-frequency phonon modes and the two-phonon process play dominant roles in the thermal transport at interfaces. In contrast, high-order phonon processes involving three to eight phonons accounted for around 8% of the interfacial thermal conductance at the TATB–PVDF interface. Phonon properties, such as the velocity and degree of phonon density overlap, are discussed for the TATB–PVDF and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX)–PVDF interfaces to estimate the interfacial thermal conductance of PBXs. This study provides a theoretical explanation for the establishment of a research method for PBX thermal transport.
Whirl dynamics of an axially functionally graded liquid-filled rotor considering shear deformation and rotary inertia
Authors: Wang Guangding , Wang Xiaole , Xie Chuanliu , Yuan Huiqun
Published: June 2022

In this study, whirl characteristics and stability of an axially functionally graded (AFG) liquid-filled rotor are investigated. The rotor is modeled based on the spinning Timoshenko beam theory. The governing equations for flexural vibration are derived via Hamilton’s principle. For pinned–pinned AFG liquid-filled rotor, the analytical solutions are derived for both the exact whirl frequency equation and the stability model. To validate the present formulations, comparative studies by numerical solutions available in the literature are conducted. Some numerical examples are performed to investigate the effects of gradient parameter, mass ratio, cavity ratio, rotary inertia, and shear deformation on the whirl speed, the critical spinning speed, and the stability of the AFG liquid-filled rotor system. The results show that these parameters have noticeable influences on dynamic behavior and stability of the rotor system. In particular, the rotary inertia and shear deformation play an important role in the stability analysis for different length rotors.
Managing offshore Australia and its resources
Authors: Gaddes Shane
Published: June 2022

The Australian Government manages over 10 million km2 of ocean, one of the largest marine jurisdictions in the world. Australia’s marine estate is a significant and growing source of wealth for all Australians. The area is used by a range of industries, government and persons for various purposes including shipping and navigation, tourism, conservation, culture and heritage, commercial and recreational fishing, oil and gas exploration and production, and defence activities. Looking ahead, activities such as carbon capture and storage (CCS) and offshore renewable energy will be active in the offshore. This paper explores the regulatory frameworks which govern interaction and co-existence of CCS projects, petroleum exploration and development and offshore wind proposals in Commonwealth waters.
Concurrent 3. Presentation for: The impact of new supply from the Perth Basin on the supply of natural gas in Western Australia
Authors: Molyneux Simon
Published: June 2022

Presented on Tuesday 17 May: Session 3 The Australian Energy Market Operator (AEMO) forecasts demand for natural gas (gas) in Western Australia will remain steady through the 2020s, but that the local production will drop below anticipated demand in the mid-2020s and again from 2030 onwards. If this situation eventuates, lack of gas production will impact the competitiveness of WA’s energy-consuming industries. This paper demonstrates that the Perth Basin has the potential to meet this supply–demand gap and augment existing sources of gas over the next 20+ years. A subsurface-led assessment of the Perth Basin’s Reserves, Contingent Resources and Prospective Resources incorporating all recent exploration well results shows that the unrisked resource potential of the Perth Basin is 7052 bcfe (7.475 PJ) with production potential up to 1100 TJ/day. The basis for these estimates will be illustrated with examples, alongside a discussion of the variables that affect the resource assessment, the impact of capacity constraints on the timing of development of Perth Basin gas, and the dynamics of the WA gas market. To access the presentation click the link on the right. To read the full paper click here
Concurrent 6. Presentation for: Environmentally assisted fatigue failure of drill pipe connections
Authors: Turnbull Judy
Published: June 2022

Presented on Tuesday 17 May: Session 6 Failure of three drill pipe connections occurred relatively early in the service life and without the more gradual reduction in operating pressure or other factors that are typically associated with a pending fatigue failure. Of the three drill pipe connections, two had fractured and the third had cracked but remained intact. The drill pipe connections were investigated to determine the mode and likely cause of the failure. Failure of the drill pipe connections was the result of fatigue that had initiated on the outside surface within the first thread root adjacent to the change in section to the barrel or at the change in the section itself. Crack propagation was radially inwards towards the connection bore. Chlorine was present in the drilling mud at low concentrations and fine pitting was identified, but overall, the rods were free of corrosion. However, positive identification of corrosion pits, albeit few in number and significant cracks emanating from said pits, suggest failure of the drill pipes could be attributed to a corrosion fatigue mechanism. This would more so be the case for two of the drill pipe connections, as the stress concentration associated with a corrosion pit would be exacerbated in the threaded region. Fatigue had subsequently propagated under bending loads, likely reverse bending loads, applied to the drill string. Such loads would likely be the result of directional drilling within strata of higher than usual hardness. To access the presentation click the link on the right. To read the full paper click here
Concurrent 7. Presentation for: Queensland’s risk-based petroleum and gas regulator
Authors: Date William
Published: June 2022

Presented on Tuesday 17 May: Session 7 Resources Safety & Health Queensland (RSHQ) is the new independent regulator for occupational safety and health in Queensland’s petroleum and gas, mining, quarrying and explosives sector. RSHQ was created by the Queensland Government on 1 July 2020 as a singular focussed statutory body. It is a stand-alone organisation quite separate from its former portfolio Department – the Department of Natural Resources Mines and Energy. RSHQ’s vision is ‘zero serious harm’. In pursuit of this lofty vision – which is defined as operations and activities free from fatality, hospitalisation and confirmed cases of disease – RSHQ applies its regulatory approach which is risk-based and data-driven. This paper outlines the regulator’s approach, values and principles to supporting the upstream petroleum sector in Queensland in order to protect its workers and meet its obligations under law. Importantly, RSHQ compliance principles and practice should be understood by operators, contractors, workers and other key stakeholders in the petroleum sector. Case studies demonstrate the efficacy of this approach as it applies to the construction, operation and decommissioning of wells, gathering systems and plant. Operators, contractors and service companies will significantly benefit from reading and hearing more from the regulator at the APPEA Conference in Brisbane in 2022. To access the presentation click the link on the right. To read the full paper click here
Concurrent 8. Presentation for: Australia well positioned to become a CCUS leader
Authors: Chatterjee Sohini
Published: June 2022

Presented on Tuesday 17 May: Session 8 Australia’s carbon capture, utilisation and storage (CCUS) sector could be set for fresh boost as oil and gas players are investing heavily in large-scale projects. In 2020, Australia emitted around 499 million tonnes of CO2-equivalent (CO2e). Country-wide, only 2.5 million tonnes of CO2 is captured and stored annually in the Gorgon CCUS project. Starting its CCUS journey on the wrong foot, Australia’s ambitious Gorgon project suffered from cost overruns, delays and much lower capture rates than planned. Nevertheless, 3 years after startup we now see renewed momentum on the back of significant budgetary support from the Federal Government, in addition to inclusion of CCUS projects in the Emissions Reduction Fund and Australian Carbon Credit Units (ACCU), which increased its value ever since. Large players are sizing up opportunities for CCUS in the country and to invest in research and development of next-generation CCUS as well as direct air capture technologies. Considering the vast CO2 storage potential in depleted oil and gas fields and saline aquifers, Rystad Energy have identified three potential storage hotspots in Australia: the northwestern hub, the mid-eastern hub and the southeastern hub. These storage hubs have a cumulative CO2 storage potential of 855 gigatonnes, that is located near to important industrial clusters and is sufficiently large, so it does not pose any barrier for CO2 storage. To access the presentation click the link on the right. To read the full paper click here
Concurrent 9. Presentation for: Evaluating Australia’s energy commodity resources potential for a net-zero emission future
Authors: Bernecker Thomas
Published: June 2022

Presented on Wednesday 18 May: Session 9 Australia’s future energy production will increasingly be focused on developing clean energy resources to achieve the goal of net zero greenhouse gas emissions by 2050. To achieve this, an understanding of Australia’s natural gas resources and greenhouse gas storage potential is needed to facilitate the rapid implementation and expansion of low-emission technologies. While Australia continues to be a net gas exporter, additional volumes are needed to support future domestic manufacturing capabilities. These extra volumes can be produced from existing accumulations that are close to infrastructure or can be unlocked from highly prospective, yet underexplored regions. The coming decade will see a dramatic change in the energy mix that supports the Australian economy. A major driver will be the development of a hydrogen production industry, initially using fossil fuels with carbon capture and storage (CCS) until the cost of hydrogen production from renewable energy becomes more reliable and competitive. The expansion and projected lower costs of renewable energy generation via solar and wind will ultimately replace much of the non-renewable energies for hydrogen production. Geoscience Australia’s energy-related work program is focused on supporting Australia’s energy transformation assessments of untapped resource potential onshore include the evaluation of geologic hydrogen occurrences, the presence and suitability of subsurface salt horizons for hydrogen storage and the distribution of effective reservoir and seal fairways for underground carbon storage. While offshore, new data from Geoscience Australia’s sea-floor mapping project will improve the understanding of suitable areas for offshore wind farms. Results from these research activities are being made publicly available either through Geoscience Australia’s data portal and its data repository. To access the presentation click the link on the right. To read the full paper click here
Concurrent 11. Presentation for: Fostering employee and community engagement through diversity, equity, and inclusion strategic goals
Authors: Campbell-Wray Jeremy
Published: June 2022

Presented on Wednesday 18 May: Session 11 As an energy technology company, our success is deeply linked with the creativity and engagement of our people. At Baker Hughes, we foster this through working to build a diverse, equitable, and inclusive work environment where everyone can bring their authentic selves and talents. A focus on diversity, equity, and inclusion (DEI) is increasingly prioritised among the investor community and is a critical component of environmental, social, and governance (ESG) work. At a global level, Baker Hughes has four strategic DEI goals that guide us on our DEI journey: Diverse Workforce, Inclusive Culture, Supplier Diversity, and Customer and Community. This paper reviews how these strategic goals are being actioned in Australia through our community engagement, industry collaboration, multicultural education, and employee resource groups. These actions have supported employees through the challenges of 2020, boosted morale, empowered teamwork, and enhanced relationships with our peers. These initiatives include environmental volunteering, coding for kids STEM events, an internal ‘culture shock’ series, and targeted donations following recent bushfires. These and other initiatives can be shared and scaled across companies or industries. To access the presentation click the link on the right. To read the full paper click here
Concurrent 12. Presentation for: Strategic decision making for late-life assets
Authors: Sikorski Adrian
Published: June 2022

Presented on Wednesday 18 May: Session 12 Aging assets late in their cumulative production cycle are increasingly common in the upstream oil and gas industry. Capturing the remaining value from these and extending their life to maximise remaining value prior to abandonment comes with a different set of challenges from the early development phase. The aim of the paper is to showcase how oil and gas companies can structure their strategic planning and decision making in relation to aging assets, identify and evaluate a spectrum of life extending operating strategies, and compare them to cessation of production, incorporating key risks, and uncertainties. Using structured decision techniques, insights about alternative late-life strategies can be gained. This information is essential to decision makers facing the common dilemma of ‘extend or end’ for assets where the bulk of the value has already been captured. We will introduce the fundamentals of Decision Quality and use them to evaluate some of the key engineering aspects associated with late-life asset management. We will showcase an example drawn from consulting for clients in Europe. The worked example addresses the following questions: How can I push the cessation of production date into the future? Does deferring abandonment justify running at a loss for a while? Are incremental investments justified given the remaining field life? How do I determine which options to pursue and develop a viable business case? How do I manage the uncertainties that might offer opportunity or catch me out? To access the presentation click the link on the right. To read the full paper click here