bluuebunny/crossref_metadata_2025 huggingface dataset:
State Policy of Environmental Convergence in Economy Transition to Sustainable Development
Authors: Zhironkin Sergey , Zhironkina Olga , Sobik Leszek
Published: June 2021

Structural shifts caused by the expansion of "green" convergent technologies significantly enhance the ecological convergence of the economies in the countries in which they determine the exit to the trajectory of sustainable development. At the same time, in an economy where the commercialization and diffusion of green technologies is constrained by structural problems, the prerequisites for environmental divergence are formed, which can finally consolidate technological lag and a long-term trend of environmental degradation. The transition from environmental divergence to convergence should be carried out in a system of convergentoriented structural policy. It presents a three-level complex: targeted changes in the reproductive structure, the proportion of production factors (the first level); impact on the sectoral, technological, market-competitive, social structures of the economy (the second level), development of research, production and financial infrastructure for the commercialization and transfer of "green" technologies (the third level).
Gaining a Competitive Advantage through Sustainability Strategy: Managerial Applications for the Mining Sector
Authors: Lazarenko Yuliia , Garafonova Olga , Marhasova Vyktoriia , Grigashkina Svetlana
Published: June 2021

In today’s business environment, sustainability is becoming an increasing issue for decision-makers, because it is concerned with sustainable development in terms of environmental, economic, and social dimensions. In view of this, mining companies worldwide understand the significance of the strategic approach to sustainability management. However, the formulation and implementation of the appropriate sustainability strategy in order to gain a competitive advantage of sustainability initiatives may be a challenging task for organizations. The paper aims to clarify the concept of sustainable competitiveness in the context of the mining industry and define the main focus areas of strategic sustainability management at the firm level. Based on a literature review a conceptual framework for strategic sustainability management of mining companies is presented, which includes key drivers and organizational factors that should be taken into account to embed efficiently the sustainability strategies into the business practice. From a management viewpoint, the presented framework can be conceptualized at the firm level as a business model which is oriented towards the achievement of competitive advantage, long-term value creation, and enhancing corporate sustainability performance of the mining operators.
Copper-Catalyzed Cross-Dehydrogenative Coupling of α-Hydroxy Esters with Nitromethane
Authors: Jiang Jin , Xiao Lili
Published: June 2021

An efficient copper-catalyzed tandem oxidation/nitroaldol reaction of hydroxyl compounds with nucleophiles is developed. In this work, β-nitro-α-hydroxy esters were prepared via cross-dehydrogenative coupling reaction using α-hydroxy esters as hydroxy compounds and nitromethane as a nucleophile. The reaction is believed to undergo an oxidation of the hydroxy group and then an addition of the generated carbonyl group. It is an example of CDC reactions related to hydroxy compounds via carbonyl intermediates.
Impact of Digit Amputation on Dogs Competing in Agility
Authors: Sellon Debra C. , Marcellin-Little Denis J. , Powers Michelle , Fernandezlopez Sarah , Cullen Kimberley L.
Published: June 2021

Objectives This work sought to determine the prognosis for dogs for return to athletic function in canine agility competitions after digit amputation.

Materials and Methods Data were collected using an Internet-based survey of owners of agility dogs with digit disorders that required amputation. Signalment and physical characteristics were compared between dogs with traumatic and nontraumatic disorders. Athletic performance before and after amputation was assessed subjectively by owner opinion and objectively for eight dogs using competition performance records.

Results Problems leading to digit amputation in 46 dogs included acute or chronic traumatic lesions (30 dogs), infection (7 dogs), neoplasia (7 dogs), and cystic lesions (2 dogs). There were no differences in signalment or physical characteristics between dogs with traumatic and nontraumatic disorders. Of the 46 dogs, 39 (84.7%) had returned to agility at the time of the survey and 94.6% of the owners (37/39) were satisfied with performance after amputation. No dog failed to return to agility as a result of the digit disorder or amputation. There was no difference in mean competition speed before and after amputation.

Clinical Significance Most agility dogs undergoing digit amputation perform satisfactorily after surgery, although modifications to performance criteria may be appropriate for some.
Extradural Peripheral Nerve Sheath Tumour at T7 Level in a 2-Year-Old Dog
Authors: Aragosa Federica , Caterino Chiara , Della Valle Giovanni , D'Aquino Ilaria , Costanza Dario , Cantile Carlo , Fatone Gerardo
Published: June 2021

The aim of this report is to describe an unusual localization of nerve sheath tumour (NST), clinical presentation, imaging, surgical management, and outcome in a 2-year-old dog. A 2-year-old female American Staffordshire Terrier presented with nonambulatory paraparesis, thoracolumbar hyperaesthesia, hindlimb hyperreflexia, and mild muscle atrophy. Computed tomography and magnetic resonance imaging revealed an extradural mass at T7-T8, without vertebral lesions. Surgical treatment consisted in resection of the soft tissue mass through dorsal laminectomy. The dog was ambulatory within 24 hours and free of recurrence at 18 months postoperatively. Histopathologic and features of immunohistochemistry were consistent with NST. The NST of this report was similar to those described before, but exhibited unusual characteristics, such as being extradural, without extension into intervertebral foramina, and being located in an atypical region (T7-T8). Moreover, survival time and relapse-free interval are greater than previously reported for similar cases.
Repair of a Radial Fracture with Radial Head Luxation in a Bugio Monkey (Alouatta caraya)
Authors: Minto Bruno Watanabe , Magalhães Thaís Vendramini , Guaita Sergio Andrés Millán , Dias Luís Gustavo Gosuen Gonçalves , Werther Karin
Published: June 2021

Bugio monkeys (Alouatta caraya) need their arms for locomotion, hygiene, and defence, and possess well-developed dexterity of their hands, depending on them for proper feeding. For this reason, appropriate treatment of thoracic limb fractures is not only essential but also challenging in this species. This report describes the successful treatment of a radial fracture associated with luxation of the radial head in a female, adult Alouatta caraya. The patient was admitted after a suspected traumatic event with a complete transverse fracture of the right radial diaphysis and subluxation of the ipsilateral radius head. Using a craniomedial approach to the radius, surgical stabilization was performed using a 1.7 mm micro series Fixin locking plate after open reduction in bone fragments. The patient had early use of the limb (24 hours postoperatively) and progressive improvement in its usual activities over the following weeks. Radiographic monitoring was performed at 30, 60, and 360 days postoperatively, and bone healing occurred with no complications. The treatment of fractures in primates is potentially challenging, requiring adaptation to primate anatomy and the specific living conditions of the species. Open reduction and stabilization of the radial fracture with a plate and manually reducing the luxated radial head effectively lead to long-term restoration of full function and of normal activities.
The Bakhtin Circle’s dialog in Vietnam
Authors: Bac Le Huy , Hang Dao Thi Thu , Phuong Le Nguyen
Published: June 2021

In this article, we use Jacques Derrida’s deconstructive method to study the influence of Mikhail Bakhtin in Vietnam in the 1990s and 2000s. By using evaluations of Bakhtin by researchers in Vietnam and around the world, we argue that he is not the only owner of the theory of dialog and polyphony. His friends, Pavel Medvedev and Valentin Voloshinov, also played important roles in defining these concepts. The Bakhtin Circle’s dialog theory is related to the sense of democracy in society. The work of Bakhtin was introduced to Vietnam in the 1980s and led to a “Bakhtin fever” throughout Vietnam. However, he has been less overrated recently. We also discover a mistake in the dialogic theory of the Bakhtin Circle. The members of the Circle said that the nature of language is dialogic, which means that whenever language is used, either in literature or in common life, it is always polyphonic. Based on this claim, novels use language to tell stories, so novels are polyphonic. The Bakhtin Circle was mistaken when labeling Dostoevsky’s novels as polyphonic and Tolstoy’s novels as monologic. In the same vein, the Bakhtin Circle strongly believed that language in poetry is always monologic. We think this claim is also wrong. Dialogicality appears in all kinds of poetic languages.
Quantum phase transitions in frustrated 1D Heisenberg spin systems
Authors: Cheranovskii V. O. , Slavin V. V. , Klein D. J.
Published: June 2021

A class of frustrated one-dimensional periodic Heisenberg spin systems formed either by triangular unit cells with spin 1/2 or by composite unit cells formed by two different structural units, triangles and small linear segments formed by an odd number of spin-1/2 is investigated. Based on perturbative processing and numerical calculations of the density matrix renormalization group method, the gapless character of the exact energy spectrum of excitation for these systems was found. Their instability with respect to regular (Peierls) oscillations of interactions between structural units is demonstrated. The corresponding critical exponents for the energies of the ground state are estimated numerically. For some frustrated systems, a quantum phase transition associated with the spin symmetry of the ground state, caused by frustration, has been discovered.
Nonlinear oscillations of topological structures in the sine-Gordon systems
Authors: Bogdan M. M. , Charkina O. V.
Published: June 2021

The nonlinear effect of the energy localization on topological inhomogeneities is investigated in the sine-Gordon systems. The regimes of nonlinear oscillations of nonequilibrium configurations of domain walls in the quasi-one-dimensional ferromagnet are described in terms of kink and breather solutions of the sine-Gordon equation. The conditions of the energy localization, i.e., the formation of breather excitations on these topological inhomogeneities, are found for the initial configurations of the dilated double kink structures. The results are obtained in the framework of the Schrödinger-type equation of the direct scattering problem associated with the sine-Gordon equation. It is shown that the final state of the evolution of the nonequilibrium topological spin structure represents the multi-frequency precessing domain wall in the ferromagnet, which radiates the continuous spectrum waves.
Temperature and thickness dependent magnetostatic properties of [Fe/Py]/FeMn/Py multilayers
Authors: Polishchuk D. M. , Nakonechna O. I. , Lytvynenko Ya. M. , Kuncser V. , Savina Yu. O. , Pashchenko V. O. , Kravets A. F. , Tovstolytkin A. I. , Korenivski V.
Published: June 2021

The magnetic properties of thin-film multilayers [Fe/Py]/FeMn/Py are investigated as a function of temperature and thickness of the antiferromagnetic FeMn spacer using SQUID magnetometry. The observed behavior differs substantially for the structures with 6 nm and 15 nm FeMn spacers. While the 15 nm FeMn structure exhibits exchange pinning of both ferromagnetic layers in the entire measurement temperature interval from 5 to 300 K, the 6 nm FeMn structure becomes exchange de-pinned in the vicinity of room temperature. The depinned state is characterized by a single hysteresis loop centered at zero field and having enhanced magnetic coercivity. The observed properties are explained in terms of finite-size effects and possible ferromagnetic interlayer coupling through the thin antiferromagnetic spacer.
Investigation of low-energy electronic excitations in quasi-one-dimensional Ising antiferromagnet CsFeCl3 · 2H2O via Raman spectroscopy
Authors: Kurnosov V. S.
Published: June 2021

The frequencies of low-lying electronic excitations in the quasi-one-dimensional antiferromagnet CsFeCl3 · 2H2O were determined by Raman spectroscopy. The lowest of them (57 cm−1) was attributed to the magnon-like excitation of the chain of Ising spins of paramagnetic Fe2+ ions. And the next one (77 cm−1) can most likely be attributed to the exciton-like one, associated with the electronic transition to the lower level of the excited orbital quasi-doublet dzx, dzy split by the spin-orbit interaction. Investigations of the splittings and shifts of Raman lines in an external magnetic field allowed us to estimate the values of the magnetic moments of the sublattices in the ground state and to determine their spatial orientation relative to the crystallographic directions.
Investigating the foot adhesion chemistry of ladybird beetles
Authors: Lim Alane
Published: June 2021

Scientists characterize the composition and wettability of adhesive molecules in beetle feet.
Determining band alignment using a single core-level photoelectron spectrum
Authors: Frank Jodi Ackerman
Published: June 2021

Spectral data from an element common to both sides of a junction indicates the band offset between them.
Team achieves highly efficient, independently controllable cascaded blue and green microLEDS
Authors: Patrick Chris
Published: June 2021

Metalorganic chemical vapor deposition grew efficient GaN-based, cascaded blue/green microLEDs with tunnel junctions, which could help develop a full-color microLEDs display for the next generation of display technology.
NaOH–urea pretreatment for biogas enhancement from algal biomass anaerobic digestion
Authors: Feng RuiZhe , Zaidi Asad A. , Li QiaoYan , Zhang Kun , Shi Yue
Published: June 2021

With the gradual increase in algal waste, its disposal has become a key problem in the field of marine environmental protection. Anaerobic digestion (AD) of algal biomass is one potential method for its treatment in a beneficial manner. However, AD of algae is hindered because of strong resilient cell walls, and hence, pretreatment of algae biomass before AD is an essential process. In this study, green algae (Enteromorpha) were used as the research substrate to explore the damage and impact of NaOH–urea pretreatment on biomass. Scanning electron microscopy and thermogravimetric analysis were used to analyze the damage of the cell wall structure of Enteromorpha via NaOH–urea pretreatment. The response surface method (RSM) was used for the optimization of pretreatment conditions to obtain the best experimental conditions. The experimental independent variables were pretreatment time, pretreatment temperature, and NaOH–urea concentration. RSM results showed that the optimal conditions are pretreatment time of 50 min, NaOH–urea concentration of 5.89%, and pretreatment temperature of −16 °C. AD was carried out under these conditions. The results showed that cumulative gas production for the control group was 231.5 ml whereas the biogas yield for best optimal conditions was 521.5 and 413 ml, respectively. In addition, AD reaction kinetics was evaluated by two mathematical kinetic models. It was found that modified Gompertz model is more suitable for describing the AD behavior.
Wave chaos enhanced light trapping in optically thin solar cells
Authors: Seim E. , Kohler A. , Lukacs R. , Brandsrud M. A. , Marstein E. S. , Olsen E. , Blümel R.
Published: June 2021

Enhancing the energy output of solar cells increases their competitiveness as a source of energy. Producing thinner solar cells is attractive, but a thin absorbing layer demands excellent light management in order to keep transmission- and reflection-related losses of incident photons at a minimum. We maximize absorption by trapping light rays to make the mean average path length in the absorber as long as possible. In chaotic scattering systems, there are ray trajectories with very long lifetimes. In this paper, we investigate the scattering dynamics of waves in a model system using principles from the field of quantum chaotic scattering. We quantitatively find that the transition from regular to chaotic scattering dynamics correlates with the enhancement of the absorption cross section and propose the use of an autocorrelation function to assess the average path length of rays as a possible way to verify the light-trapping efficiency experimentally.
Characterization and efficient Monte Carlo sampling of disordered microphases
Authors: Zheng Mingyuan , Charbonneau Patrick
Published: June 2021

The disordered microphases that develop in the high-temperature phase of systems with competing short-range attractive and long-range repulsive (SALR) interactions result in a rich array of distinct morphologies, such as cluster, void cluster, and percolated (gel-like) fluids. These different structural regimes exhibit complex relaxation dynamics with marked heterogeneity and slowdown. The overall relationship between these structures and configurational sampling schemes, however, remains largely uncharted. Here, the disordered microphases of a schematic SALR model are thoroughly characterized, and structural relaxation functions adapted to each regime are devised. The sampling efficiency of various advanced Monte Carlo sampling schemes—Virtual-Move (VMMC), Aggregation-Volume-Bias (AVBMC), and Event-Chain (ECMC)—is then assessed. A combination of VMMC and AVBMC is found to be computationally most efficient for cluster fluids and ECMC to become relatively more efficient as density increases. These results offer a complete description of the equilibrium disordered phase of a simple microphase former as well as dynamical benchmarks for other sampling schemes.
Numerical study of the magnetohydrodynamic flow instability and its effect on energy conversion in the annular linear induction pump
Authors: Zhao Ruijie , Dou Xiaohui , Zhang Desheng , Huang Jun
Published: June 2021

A numerical model of annular linear induction pump with a full-scale pump channel is created to study the scale-dependent instability of the magnetohydrodynamic flow. The magnetic-fluid coupling effect is implemented by modifying the underlying governing equations and constraints. The model authenticity is validated by comparing the simulated pressure difference, as well as the pressure pulsation, with the previous experimental data. The flow patterns at different flow rates corresponding to different magnetic Reynolds numbers are depicted from both the azimuthal and meridian viewpoints, and the periodicity of the occurring vortex flows is found in the pump. By analyzing the different mechanisms contributing to the fluid kinetic energy, it is found the competition between the axial components of the Lorentz force and pressure gradient dominates the flow evolution in the pump channel. The magnetic-fluid coupling effect is found to amplify the disturbances in either the magnetic field or the fluid field. It is even effective within the uniform externally imposed magnetic field and inlet velocity only if a disturbance exists in the initial flow. Increase in the cycle number of disturbance can enhance the flow stability and induce smaller vortex flows. Finally, different mechanisms of energy conversion in the pump are analyzed and it is found that the sudden occurrence of vortex flows can induce large current density, which significantly increases the Ohmic dissipation and decreases the efficiency of energy conversion from magnetic field into the fluid. The relatively large Ohmic dissipation in the fluid is the main reason for the low efficiency of such a device.
Model fusion with physics-guided machine learning: Projection-based reduced-order modeling
Authors: Pawar Suraj , San Omer , Nair Aditya , Rasheed Adil , Kvamsdal Trond
Published: June 2021

The unprecedented amount of data generated from experiments, field observations, and large-scale numerical simulations at a wide range of spatiotemporal scales has enabled the rapid advancement of data-driven and especially deep learning models in the field of fluid mechanics. Although these methods are proven successful for many applications, there is a grand challenge of improving their generalizability. This is particularly essential when data-driven models are employed within outer-loop applications like optimization. In this work, we put forth a physics-guided machine learning (PGML) framework that leverages the interpretable physics-based model with a deep learning model. Leveraging a concatenated neural network design from multi-modal data sources, the PGML framework is capable of enhancing the generalizability of data-driven models and effectively protects against or inform about the inaccurate predictions resulting from extrapolation. We apply the PGML framework as a novel model fusion approach combining the physics-based Galerkin projection model and long- to short-term memory (LSTM) network for parametric model order reduction of fluid flows. We demonstrate the improved generalizability of the PGML framework against a purely data-driven approach through the injection of physics features into intermediate LSTM layers. Our quantitative analysis shows that the overall model uncertainty can be reduced through the PGML approach, especially for test data coming from a distribution different than the training data. Moreover, we demonstrate that our approach can be used as an inverse diagnostic tool providing a confidence score associated with models and observations. The proposed framework also allows for multi-fidelity computing by making use of low-fidelity models in the online deployment of quantified data-driven models.
Fluid structure interaction between a pendulum and focused breaking waves
Authors: Bos R. W. , Wellens P. R.
Published: June 2021

To study how an extreme wave load on a maritime structure causes structural deformation, an experiment is conducted to measure the response of a one degree-of-freedom pendulum in a focused, breaking wave. The tube that makes up the base of the pendulum covers almost the entire width of the tank so that three-dimensional effects can be considered small. The experiment varies the focus location with respect to the position of the pendulum as well as the vertical clearance between pendulum and mean free surface. Although the energy of the wave input was the same for all experiments, the response of the pendulum varied greatly with small variations of initial vertical clearance and wave focus location, with the wave breaking farthest away from the pendulum causing the largest response. A reduced-order model for the response of the pendulum shows the same behavior when initial clearance and focus location are varied. Even when initial clearance and focus location were kept the same between tests, large variability of the pendulum response was observed, meaning that the impulse exerted by the wave must have been different. This is different from the literature on breaking waves against rigid walls that found that local pressures show variability between experiments but that the impulse typically is the same. The experimental data and a description have been made available.
Structural organization of space polymers
Authors: McGeoch Julie E. M. , McGeoch Malcolm W.
Published: June 2021

Extraterrestrial polymers of glycine with iron have been characterized by mass spectrometry to have a core mass of 1494 Da with dominant rod-like variants at mass to charge ratios of 1567 and 1639 [McGeoch et al., “Meteoritic proteins with glycine, iron and lithium,” arXiv:2102.10700 (2021)]. Several principal macro-structural morphologies are observed in solvent extracts from a chondritic Vigarano class alteration type 3 meteoritic material. The first is an extended sheet of linked (three-legged) triskelia containing the 1494 Da core entity that encloses gas bubbles in the solvent. A second is of fiber-like crystals found here, via x-ray diffraction, to be multiple-walled nanotubes made from a square lattice of the 1494 Da polymer. A third is a dispersion of floating phantom-like short tubes of up to 100 μm length with characteristic angled bends that suggest the influence of a specific underlying protein structure. Here, it is proposed that the angled tubes are the observable result of a space-filling superpolymerization of 1638 Da polymer subunits guided by the tetragonal symmetry of linking silicon bonds. Distorted hexagonal sheets are linked by perpendicular subunits in a three-dimensional hexagonal diamond structure to fill the largest possible volume. This extended very low-density structure is conjectured to have dominated in a process of chemical selection because it captured a maximum amount of molecular raw material in the ultra-low density of molecular clouds or of the proto-solar nebula. This could have led ultimately to the accretion of the earliest planetary bodies.
Numerical study of hole formation in a thin flapping liquid sheet sheared by a fast gas stream
Authors: Agbaglah G. Gilou
Published: June 2021

This study reports aerodynamics effects of a fully developed double-shear layer gas flow in the perforation and disintegration of a thin liquid sheet using three-dimensional numerical simulations. A double-shear layer gas flow, where a thin quiescent gas layer is sandwiched between the two fast moving gas layers, is first simulated up to a statistically steady state. The downstream dynamics of the gas shear layers shows vortex shedding and three-dimensional rib-like vortical structures, similar to the wake of a bluff body. This gas flow is then used as the initial condition for a liquid-gas simulation, where the liquid phase is sandwiched by the top and bottom fast gas streams. A thin liquid sheet with a thickness of 25 μm is considered using air/water conditions. The liquid sheet oscillates and small holes, preceded by craters surrounded by ripples, are formed. The thinning of the liquid sheet, spanwise corrugations, and vortex separations within the liquid-gas boundary layer are shown to govern the dynamics of the liquid sheet. A localized pressure jump is also observed inside the liquid sheet and precedes the rupture of the liquid sheet by pushing the liquid away in the span direction. The holes formed subsequently grow in size, collide and merge with each other, and break the liquid sheet into multiple droplets.
Fine and hyperfine interactions in 171YbOH and 173YbOH
Authors: Pilgram Nickolas H. , Jadbabaie Arian , Zeng Yi , Hutzler Nicholas R. , Steimle Timothy C.
Published: June 2021

The odd isotopologues of ytterbium monohydroxide, 171,173YbOH, have been identified as promising molecules to measure parity (P) and time reversal (T) violating physics. Here, we characterize the Ã2Π1/2(0,0,0)−X̃2Σ+(0,0,0) band near 577 nm for these odd isotopologues. Both laser-induced fluorescence excitation spectra of a supersonic molecular beam sample and absorption spectra of a cryogenic buffer-gas cooled sample were recorded. In addition, a novel spectroscopic technique based on laser-enhanced chemical reactions is demonstrated and used in absorption measurements. This technique is especially powerful for disentangling congested spectra. An effective Hamiltonian model is used to extract the fine and hyperfine parameters for the Ã2Π1/2(0,0,0) and X̃2Σ+(0,0,0) states. A comparison of the determined X̃2Σ+(0,0,0) hyperfine parameters with recently predicted values [Denis et al., J. Chem. Phys. 152, 084303 (2020); K. Gaul and R. Berger, Phys. Rev. A 101, 012508 (2020); and Liu et al., J. Chem. Phys. 154,064110 (2021)] is made. The measured hyperfine parameters provide experimental confirmation of the computational methods used to compute the P,T-violating coupling constants Wd and WM, which correlate P,T-violating physics to P,T-violating energy shifts in the molecule. The dependence of the fine and hyperfine parameters of the Ã2Π1/2(0,0,0) and X̃2Σ+(0,0,0) states for all isotopologues of YbOH are discussed, and a comparison to isoelectronic YbF is made.
Early stage evolution of naturally developing Görtler streaks
Authors: Huang Ganglei , Si Wufei , Lee Cunbiao
Published: June 2021

This is a companion paper to a previous study of hypersonic boundary layer transition over a concave wall [Huang et al., “Inner structures of Görtler streaks,” Phys. Fluids 33, 034116 (2021)]. Experiments are performed in a Mach 6.5 quiet wind tunnel using CO2-enhanced filtered Rayleigh scattering flow visualization, PCB fast-response pressure sensors, and a high-frequency Schlieren technique to investigate naturally developing Görtler streaks. This is the first time that naturally developing Görtler streaks have been visualized using the Rayleigh scattering technique in a hypersonic flow. The results show that three-dimensional waves can be clearly visualized inside the Görtler streaks. More importantly, these waves are amplified owing to Görtler instability, contributing to the formation of Görtler streaks and mushroom-like structures. Thus, the three-dimensional waves can be considered to be basic structures inside Görtler streaks and to play a crucial role in boundary layer transition.
Demonstrating a magnetic steering of the thrust imparted by the magnetic nozzle radiofrequency plasma thruster
Authors: Imai Ryoji , Takahashi Kazunori
Published: June 2021

Axial and horizontal components of the thrust imparted by a magnetic nozzle radio frequency plasma thruster are measured by attaching the thruster to a pendulum balance, where two horizontal solenoids are additionally mounted near the thruster exit to steer the magnetic nozzle. The thruster is operated at the rf power of 500 W in argon. The two-dimensional profiles of the ion saturation current of a Langmuir probe show the plasma plume deflected along the magnetic field lines. The measured axial thrust is about 1.6 mN for all the horizontal solenoid current, while the horizontal thrust increases from 0 to 0.2 mN when increasing the horizontal solenoid current. These results indicate that the thrust vector can be continuously changed within the angle of several degrees, demonstrating the thrust vector control by the magnetic steering.
Co-creation of knowledge – an effective mechanism for managing decommissioning stakeholders
Authors: Tung Aaron
Published: June 2021

Despite the fact that it has been 26 years since the events of Brent Spar, stakeholder impacts are still continuing to affect the performance of oil and gas decommissioning projects. If stakeholders are not well managed, not only can they have devastating consequences on project costs and
schedules, but there may also be further social and environmental implications as well. On the flip side, if organisations can get it right, stakeholders can also bring about various benefits. An ongoing research project to enhance project managers’ understanding of the United Kingdom and Australian decommissioning landscapes found that knowledge creation through interactions between organisations and stakeholders has brought about benefits to various decommissioning projects, including the Maureen, Miller, and Brae decommissioning projects. The concept of co-creation of knowledge has been mentioned in many academic works to be an effective mechanism for managing stakeholders in the field of sustainable development, product development, and healthcare. However, the explicit links between co-creation of knowledge and decommissioning have yet to be drawn. This
article proposes that co-creation of knowledge be adopted as a best practice to manage decommissioning stakeholders. By actively co-creating knowledge with stakeholders and extending the existing body of knowledge in decommissioning, the extent of alignment and trust between organisations and stakeholders are strengthened, creating long-term relationships that greatly improves the probability of stakeholder acceptance and approval.
Two companies collaborating to make real safety improvements: Arrow Energy, Shell QGC and the Queensland coal seam gas industry
Authors: Zaunbrecher Michelle L. , Johnston Timothy , Wood Rachael
Published: June 2021

Arrow Energy (Arrow) and Shell QGC have strong collaboration on safety, contributing to direct improvements. This collaboration represents over 50% of exposure manhours for the Queensland CSG sector. The following important trends were apparent.
Personal safety injuries largely with low severity consequence – a large proportion were at, or near, full incident severity potential.
First aid and recordable injuries predominantly caused by slip/trips, strains, caught-between, line of fire/tools/falls from height.
High potential incidents (HiPos), or serious near misses, largely have different causes including: land transport; process safety; drops/heights; electrical; excavation; automated equipment.
Recordable incidents resulted predominantly (over 75%) from routine, low risk activities (tasks not controlled under permit/critical control), and most involved workers conducting activities when working alone (75% or more).

These critical insights differ from the industry accepted safety paradigm, whereby a greater number of low-consequence level incidents will likely have a direct numerical ratio relationship to more serious incidents (HiPos or fatalities), known as Heinrich’s triangle. This is because the causes of the low vs high severity incidents are different for the Arrow and Shell QGC datasets; addressing the causes of low severity incidents will not automatically in turn address the causes of the high severity incidents. Both companies have demonstrated marked improvements in safety performance of recordables when focused improvement programs were applied, and show that improvements to the total recordable case frequency rate (TRCFR) and low severity incidents should not be seen as impenetrable across the industry. Sharing of insights and trends then resulted in these organisations sharing their improvement strategies, most notably the Assist and Assure Program, and the Contractor Partnerships Program. Arrow was able to purposely address these trends, noting good improvements (TRCFR from 3.5 to 1.8); and drilling-related recordable incidents from eight in 2018 to just one in 2019, and 2020. In Shell QGC, the projects (construction) area saw a dramatic improvement with 583 days TRC-free (7 July 2017–11 January 2019); the direct result of leadership programs, workforce engagement and partnership programs with their two main construction contractors. The Assist and Assure Program in the drilling area, saw the recordable incidents improve to just two in 2017, compared with seven (2015) and six (2016).
Australia–Asia power link: environmental and cost assessment
Authors: Gordonnat Jeremy , Hunt James
Published: June 2021

Australia’s high potential for renewable energy generation and the high carbon content of Southeast Asian electricity create favourable conditions for a high voltage direct current (HVDC) power link connecting Australia and Southeast Asia. This interconnector would link predominantly large-scale solar farms located in northern Australia to Singapore given its central location within Southeast Asia, high reliance on fossil fuel for its power generation, high demand growth and limited renewable potential and land surface. This paper presents the expected annual reduction of greenhouse gas emissions that could be offered by an Australia–Singapore power link accounting for the entire life cycle including HVDC cable embodied carbon and emissions related to cable transport, installation, operations and decommissioning phases. A levelised cost of electricity has been calculated to assess the cost-attractiveness of projects of this nature compared to gas-fired plants accounting for capital costs, variable costs, fuel cost as well as the subsea cable cost. In a world of growing environmental concerns, the decreasing cost of solar photovoltaic combined with future stringent carbon policies will gradually result in a competitive levelised cost of electricity of large-scale solar projects coupled with an intercontinental power link in comparison to local gas-fired power generation.
Velocity anomalies and out-of-plane reflections in Barnicarndy 1, Canning Basin
Authors: Zhan Y.
Published: June 2021

Barnicarndy 1 was drilled as a stratigraphic well and penetrated 2585m of clastic sedimentary rocks overlying an angular unconformity composed of Proterozoic dolomite basement near SSE end of the eponymous graben (previously known as the Waukarlycarly Embayment) of the Canning Basin. The post-drilling data exhibited several types of anomalies and inconsistencies, including ultra-slow velocity of the vertical seismic profile (VSP) within the top 210m, substantially high velocity from 210 to 1390m, poor synthetic–seismic correlation, and discrepancies between the prognosis and actual depths. The VSP shows that the uppermost sedimentary section has an average velocity of less than 1000m/s, which is unrealistically slow and probably caused by a systematic time delay in the data acquisition. Such a delaying effect was removed when calculating the VSP interval velocity, which had reasonable consistencies with sonic velocity and lithological packages. The consistencies verify that the sections from 210 to 1390m have high velocities that are beyond the range of offset wells at equivalent depths and do not follow an expected trend along most of the well trajectory. Quantitative analyses of multiple synthetic correlations suggest that the depth discrepancies in the prognosis are not related to pre-drilling seismic interpretation, as the two-way time picks for major boundaries mostly match what has been penetrated in Barnicarndy 1. Two thirds of the depth error for basement prognosis comes from the unexpected high velocity in the shallow formations. The velocity anomalies indicate that the Barnicarndy Graben possibly has a complex history of tectonic movement, and thick sections could have been eroded during the Late Triassic. The remaining discrepancy in depth prognosis for the basement is related to the out-of-plane seismic reflection near the SSE end of the graben. The steeply dipping basement causes out-of-plane issues for 2D seismic data, and the Kidson seismic survey images the shallower basement reflected from further south, rather than what is vertically below the survey route.
Minimising the risk of hydrogen embrittlement (HE) and hydrogen assisted stress cracking (HASC) within steel lifting products used in the marine environment
Authors: Burgess Ben
Published: June 2021

Hydrogen embrittlement (HE) and hydrogen assisted stress cracking (HASC) are processes that detrimentally affect certain steels. These processes are understood and well documented. In recent years there has been an accumulation of product failures involving steel lifting components in the offshore industry. These failures have individually been investigated and confirmed as the result of HE and HASC. There continues to be an assumption that steel lifting components that comply with international standards are suitable for use offshore; however, the corrosive environment and effects of dynamic load amplification on lifting components in the offshore environment significantly increase their susceptibility to HE and HASC. Our intention is to provide the offshore industry with technical guidance on the correct material selection in steel lifting components, over and above the requirements of international standards, to mitigate the risk of failure caused by HE and HASC. The definition of toughness in metallurgy and lifting is the ability of the material to absorb energy and to plastically ‘deform’ without fracturing. Our research highlights that a high-grade steel’s hardness and toughness is critical.
A complementary method of assessing clay stabilisers used in hydraulic fracturing applications
Authors: Dupont Jeff , Dawson Jeff , Mitchell Richard
Published: June 2021

Reservoirs with clays that swell or migrate can potentially impair production (Johnson 1952; Nasr-El-Din et al. 1999). When these clays are present, it is advantageous to use clay stabilisers to mitigate this damage potential (Fink 2011). The oil and gas drilling and hydraulic fracturing industry has adopted several clay assessment methods including analytical procedures such as X-ray diffraction (XRD) and scanning electron microscopy (SEM), and performance testing methods such as capillary suction test (CST) and the roller oven test. This paper describes a new performance test method for inhibitors used in shale reservoirs that complements the existing methods such as XRD and CST. A modified core flow method has been developed using unconsolidated core material that mimics a fracture network and indirectly measures the clay swelling and migration potential. In this procedure, a packed column composed of tightly sized shale material is used to simulate an infinite fracture network. Treatment fluids are then pumped through the column at constant rate while measuring pressure drop. The relative pressure change, together with the turbidity of the effluent, allows easy assessment of the clay stabiliser.
Micellar Catalysis and Reactivity in Nanostructured Ionic Liquids: Two Sides of the Same Coin?
Authors: Kahlon Navjot K. , Weber Cameron C.
Published: June 2021

Micellar catalysis has been established for several decades although has recently been gaining attention as a method for enabling greener chemical synthesis. While the main reason underpinning the modern renaissance of micellar catalysis is the ability to perform reactions using water as a solvent, the use of micellar conditions influences reactivity in ways that do not occur in homogeneous solutions, owing to the confinement of reagents within the micelle and their interactions with micellar headgroups. Recently, it has been discovered that ionic liquids, low-melting salts, can form amphiphilic nanostructures with bicontinuous polar and non-polar domains. Here, we review the evidence to date of the influence of ionic liquid nanostructure on reactivity in comparison with the known influence of micellar catalysis to examine the relationship between these approaches to reactivity in structured media. Key benefits and limitations of each approach are highlighted, with areas likely to benefit from the development of a deeper understanding of reactivity in nanostructured ionic liquids identified.
QTL mapping of lodging tolerance in soybean
Authors: Sun Maolin , Li Na , Yu Kuanwei , Zhan Yuhang , Yuan Ming , Teng Weili , Li Wenbin , Zhao Xue , Xiao Jialei , Han Yingpeng
Published: June 2021

Lodging is an important agronomic trait that affects soybean seed yield. In this study, a recombinant inbred line (RIL) population derived from ‘Zhongdou 27’ × ‘Jiunong 20’ (including 112 lines) was used to identify quantitative trait loci (QTL) associated with lodging of soybean. A genetic map of 2050.27 cM was previously constructed using 4412 single nucleotide polymorphism (SNP) bins in this population. Three major QTL were identified in the single environment for 3 years, accounting for 12.38–16.5% of the phenotypic variation. Among these QTL, qldg-1 was stable for 3 years and qldg-2 was stable for 2 years. QTL by environment interactions (QEI) mapping was also used to detect QTL. A total of 14 QTL were detected, which could explain 2.62–11.28% of the phenotypic variation. The constructed residual heterozygous lines (RHL) were used for the verification of qldg-1 and qldg-2, and the results showed that these two QTL could significantly improve lodging resistance. In addition, genes in the confidence interval of qldg-1 and qldg-2 were designed to predict the candidates. The results of quantitative real-time PCR (qRT-PCR) verification of five genes revealed that two genes (Glyma.17G048100 and Glyma.09G239000) were expressed differentially during the dynamic stages between the parents, demonstrating that these two were the candidates associated with soybean lodging. The QTL and candidate genes related to soybean lodging identified in this study will be of great significance to the future soybean molecular-assisted breeding for lodging resistance.
Reservoir water-quality simulation using simplified mathematical models (case study: Seymareh Reservoir)
Authors: Heidarzadeh Nima , Mahdavi Hesam , Yaghouti Mahtab
Published: June 2021

In this research, the performance of simple mathematical models was evaluated for predicting total dissolved solids (TDS), biochemical oxygen demand (BOD) and nitrate (NO3–) in a case study, the Seymareh Reservoir located in the south-west of Iran. The accuracy of the mathematical models was compared with a two-dimensional model, called CE-Qual-W2, and real observations. The models were considered as two different input-data scenarios and one scenario for applied mathematical equations (completely mixed reactor). The modelling period was from October 2012 to September 2013. The results of the simple mathematical models show an acceptable performance with the mean relative error (MRE) of 10.8–73.8 compared with the complex CE-Qual-W2 model, whereas they require fewer input data and take less time to execute. To verify the accuracy of the equations, the results were also compared with the sampling data from the reservoir. The best performance of the proposed mathematical models showed a MRE of ~10.8%, 31.5% and 16.5% for TDS, BOD and NO3– respectively. These findings suggest using such simple models for screening/feasibility studies and also to model water quality in several dams across the basin to save time and cost.
From hidden order to antiferromagnetism: Electronic structure changes in Fe-doped URu
2
Si
2
Authors: Frantzeskakis Emmanouil , Dai Ji , Bareille Cédric , Rödel Tobias C. , Güttler Monika , Ran Sheng , Kanchanavatee Noravee , Huang Kevin , Pouse Naveen , Wolowiec Christian T. , Rienks Emile D. L. , Lejay Pascal , Fortuna Franck , Maple M. Brian , Santander-Syro Andrés F.
Published: June 2021

Significance

The transition of

U
R
u

2

S
i

2

to an ordered state below 17.5 K has been a puzzle of condensed matter physics for over 30 y, earning it the soubriquet of the hidden-order (HO) state. Intriguingly, pressure or doping can transform the HO into an antiferromagnetic (AFM) state, of well-known symmetry. Here, by angle-resolved photoemission spectroscopy, the electronic structure of

U
R
u

2

S
i

2

in the HO phase is directly compared with its AFM counterpart. This reveals topographically identical Fermi surfaces; however, they differ by the size of some of their pockets. The overall nonrigid change of the electronic structure across the AFM/HO phase boundary indicates that a change in the interaction strength between states near the Fermi level is essential to stabilize the HO state.
Acute
Trem2
reduction triggers increased microglial phagocytosis, slowing amyloid deposition in mice
Authors: Schoch Kathleen M. , Ezerskiy Lubov A. , Morhaus Michaela M. , Bannon Riley N. , Sauerbeck Andrew D. , Shabsovich Mark , Jafar-nejad Paymaan , Rigo Frank , Miller Timothy M.
Published: June 2021

Significance

Alzheimer’s disease (AD) remains a significant health burden within the aging population and currently lacks therapies that effectively target pathological events to halt the development or progression of AD. The gene
TREM2
appears to influence abnormal protein accumulations in AD through the brain’s immune cells; however, it is not clear if and when TREM2 might be targeted in disease to limit pathology or the immune response. We used antisense oligonucleotides (ASOs) to reduce
Trem2
levels in the mouse brain at specific times in disease and investigated amyloid protein accumulations, microglial responses, and genetic signatures. ASO-mediated
Trem2
lowering during late-stage disease reduced amyloid pathology, which may have been triggered by an acute activation of microglia to engulf and clear amyloid deposits.