bluuebunny/crossref_metadata_2025 huggingface dataset:
Using CT to test the damage characteristics of the internal structure of expansive soil induced by dry–wet cycles
Authors: Huang Zhen , Zhang Hai , Liu Bin , Wei Bingxu , Wang Hui
Published: July 2021

Damage to the internal structure of expansive soil under dry–wet cycles is the key factor for engineering damage to expansive soil. The expansive soil in Nanyang, Henan Province, China, is taken as the research object, and the damage characteristics of the internal structure of the expansive soil under dry–wet cycles are discussed. Computed Tomography (CT) images of the internal cracks of the expansive soil after zero to eight dry–wet cycles under different initial moisture contents were obtained using a CT machine, and the development of the internal structural cracks of the expansive soil was analyzed. The damage variable of the expansive soil defined by the ME value of CT and the relation between the damage variable, the number of dry–wet cycles, and the initial control moisture content are described. An empirical nonlinear damage model of the internal structure of expansive soil is established. Finally, the rationality of defining the damage variable by the ME value of CT is verified by the test results of the low-stress shear strength of the expansive soil. The results show that the first to fourth dry–wet cycles have great influence on the microstructure of the expansive soil and that internal microcracks are noticeably developed. With the increase in dry–wet cycles, the SD value increases gradually, and the anisotropy of the expansive soil becomes more significant. The dry–wet cycles result in the weakening of the connection between the particles of the expansive soil and in the damage of the internal structure, which is a nonlinear cumulative process. The ME value can be used to describe the damage evolution characteristics of expansive soil after dry–wet cycles.
Deferred maintenance – a major industry challenge?
Authors: Seccombe Kylie , O'Keeffe Derrick
Published: July 2021

This paper identifies key areas of concern regarding the use of deferral as a maintenance management tool. As the national regulator for offshore petroleum operations and greenhouse gas storage activities, National Offshore Petroleum Safety and Environmental Management Authority is uniquely positioned to observe the various processes and tools applied by industry in the management of maintenance for offshore facilities, including impacts on safety and the environment, while acknowledging the need for business sustainability. This Extended Abstract provides a regulator’s perspective on the use of ‘maintenance deferral’ by industry as a tool for balancing competing priorities, while ensuring the risks to people and the environment are reduced to a level that is as low as reasonably practicable. It highlights the pitfalls of maintenance deferral that may negatively influence safety and environmental performance over the life of a facility (from construction through to decommissioning) as well as on the business’ bottom line. Learnings identified from non-compliances, improvement recommendations and incidents to promote efficient and effective learning are shared to further enhance existing good practices across the industry.
Salt in the Vulcan sub-basin, NW Australia: observations from high-quality 3D seismic data and implications for palaeogeography
Authors: Molyneux Simon , Doyle Stephen
Published: July 2021

The Vulcan sub-basin is one of the few places in Australia where tectonic features (i.e. diapirs) associated with a mobile substrate can be found. In this presentation one of these features, the Paqualin diapir, and its environs will be described and discussed using the new regional NOVAR MC3D prestack depth migrated seismic dataset. The extent of the NOVAR MC3D seismic dataset makes it possible, for the first time, to integrate the observation of c. 600m of interbedded halite and anhydrite in the Paqualin-1 well, local fault geometries indicative of the movement of a mobile layer and regional tectonic features consistent with the presence of a mobile substrate. In this presentation the observations will be integrated with global analogues, regional palaeogeographic interpretations to refine models for the origin and spatiotemporal distribution of mobile layers in the Vulcan sub-basin.
New insights into the deep-water Otway Basin – Part 3. Petroleum system modelling
Authors: Schenk Oliver , Grosjean Emmanuelle , Edwards Dianne S. , Boreham Christopher J. , West Tekena , Karvelas Alexander
Published: July 2021

The Otway Basin is a broadly northwest–southeast trending basin and forms part of a rift system that developed along Australia’s southern margin. It represents an established hydrocarbon province with mostly onshore and shallow-water offshore discoveries. However, the outboard deep-water Otway Basin, with water depths up to 6300m, is comparatively underexplored and can be considered a frontier area. Following the completion of a basin-wide seismic depth-imaging program (Part 1) and insights from the revised seismic interpretation (Part 2), we have developed a comprehensive petroleum system modelling (PSM) study by integrating these data and findings (Part 3). Together, the studies have resulted in an improved understanding of the hydrocarbon prospectivity of the deep-water areas of the basin. Given the sparsity of data outboard, almost all legacy PSM studies have been focused either on the onshore or shallow-water areas of the basin and primarily on their thick Lower Cretaceous depocentres. The limitations of legacy seismic datasets resulted in a high degree of uncertainty in the derivative interpretations used as input into PSM studies. In addition, the paucity and poor quality of data in the deep-water area reduced confidence in the understanding of the basin evolution and spatial distribution of depositional environments through time. The newly acquired 2D seismic survey and reprocessed legacy data, with calibration via several wells across the basin, have improved confidence in our understanding of the tectonostratigraphic evolution of the basin (Part 2). The study presented herein integrates products from the work in Part 2 into a petroleum system model with the primary objective being to better understand the petroleum systems across the deep-water Otway Basin.
Low-salinity carbonated water injection in sandstone reservoirs: interplay between oil recovery improvement, salinity and fines migration
Authors: Sadati Ehsan Yazdani , Siahvashi Arman , Hurter Suzanne
Published: July 2021

Carbonated water injection (CWI) is described as a chemical-enhanced oil recovery method in which CO2-enriched water is injected into oil reservoirs as a displacing fluid. Although confirmed by many that a considerable amount of recovery improvement is attainable through CWI in both lab and field scales, the interaction of salinity on the performance of CWI and its potential fines migration is not very well understood. This study examines the efficiency of oil recovery improvement during low-salinity carbonated water injection (LSCWI) in a sandstone reservoir, while total dissolved salt concentration varies. To this end, a series of coreflooding experiments were performed on homogeneous sandstone cores at 80°C and 2000psi, and the amount of oil recovery was measured. From the experiments, it was observed that CWI could extract more crude oil than conventional water flooding in all salinities. In particular, the highest oil recovery was observed in the lowest salinity (61.2% in CWI and 42% during water flooding), indicating that by carbonating low-salinity water, oil recovery is enhanced by 20%. Moreover, the influence of salinity reduction on recovery enhancement was such that 9% of recovery improvement observed during conventional water flooding when salinity decreased from 40000 to 1000ppm. At the same time, this improvement was around 15% for CWI, suggesting that salinity reduction can be more effective in CWI rather than water flooding in recovery improvement. It was also found out that while recovery improvement and fines migration are both highly affected by water salinity, there is a synergy between the efficiency of CWI and onset of fines migration, which is one of the underlying mechanisms in oil recovery improvement during LSCWI into clay-containing sandstone reservoirs.
Novel collaborative P&A campaign using inflatable packers and bismuth alloy plugs
Authors: Bensaied Adam , Farag George , Fulks Jeff
Published: July 2021

Chevron Australia, a leading O&G operator on the Australian North West Shelf, executed a plug and abandonment (P&A) campaign where 34 wells (19 offshore and 15 onshore) incorporated a novel bismuth alloy barrier system to the traditional cement plug. The challenge of isolating shallow gaseous zones that cause sustained casing pressure and free gas flow to surface behind the production casing was overcome by this new innovative use of collaborative technologies to provide an optimised P&A solution. The offshore/onshore P&A campaign was completed successfully with significant cost savings, eliminating the lengthy process of section milling more than 100ft of casing on each well, providing a long-term bismuth alloy barrier in the well and eliminating the potential need to reenter the well later due to a leaking cement plug.
Australia offshore well inventory characterisation and decommissioning cost saving opportunities through cap rock restoration and rigless/riserless techniques
Authors: Murphy Christopher , Higgins Stuart A.
Published: July 2021

This research utilises the Geoscience Australia and NOPIMS public database to characterise the national inventory of active offshore oil and gas (O&G) wells and, through representative examples of dry and wet completions, establish the current well decommissioning cost opportunities associated with using riserless and rigless techniques to restore cap rock. These techniques have been successfully applied in the Gulf of Mexico (GoM) and this study explores the potential savings and barriers to adoption in the Australian offshore operating and regulatory context. Third party studies (Bills 2018; Wood Mackenzie 2020) have reported Australian O&G decommissioning cost estimates in the range of USD 33–49 billion over the next 30–40 years. The well decommissioning contribution to the total project cost has been estimated at 49% (OGUK 2020). This cost is materially significant to the economic life of the asset, the operator’s financial liability and a significant cost burden to the Federal Government through Petroleum Resource Rent Tax (PRRT) offsets. In this context there is a paucity of detail and transparency for well decommissioning cost estimates, to establish whether there are cost saving opportunities whilst still maintaining an acceptable level of risk both during plug and abandonment (P&A) operations and in the longer term when relinquished back to the Federal Government. This study illustrates how and to what extent the Australian offshore Federal well inventory could be decommissioned using cap rock restoration and rigless/riserless techniques and proposes a staged strategy to realise a progressive cost reduction of 21–41% over the base estimate of circa USD 4.08 billion benchmarked with OGUK (2019). This significant cost reduction aligns with the OGTC (2019) technology roadmap target of 35% supported in part by the pursuit of a rigless and riserless well decommissioning philosophy.
Structural containment in the Port Campbell Embayment and on the Mussel Platform, Otway Basin, Victoria
Authors: Langhi Laurent , Swierczek Ernest , Strand Julian , Divko Louise Goldie , Whittam David , Ross Andrew
Published: July 2021

As part of the Victorian Gas Program, new geological modelling of the Cretaceous to recent deposits in the Port Campbell Embayment and the Mussel Platform was carried out to investigate fault seal and trap integrity. Structural characterisation of the Late Cretaceous to present-day sedimentary sequence highlights cross-cutting fault trends defining potential structural traps containing Waarre Formation reservoirs. The fault trends are primarily controlled by Cretaceous-Paleogene extension and are reactivated during the Paleogene. Seismic facies in the top seal suggest an N-S environmental shift from open-marine to proximal nearshore marine. The quantification of fault membrane seals suggests that while reservoir-on-reservoir juxtapositions may enable some degree of lateral flow, efficient trapping relying on juxtaposition seal against the Belfast or Skull Creek mudstones is widespread. Fault geomechanics suggests that NW-SE and E-W faults accommodated most of the extensional strain and could have been associated with increased vertical structural permeability; however, there are no leakage indicators to support widespread vertical migration. These results do not support previous assumptions that fault seal integrity and top seal bypass represent a critical and widespread issue within the nearshore Otway Basin.
Moomba carbon capture and storage case study: material emissions reduction at Moomba plant
Authors: Harley Nick
Published: July 2021

Carbon capture and storage (CCS) is essential for meeting the Paris agreement global emissions targets – all identified pathways to net zero 2050 emissions require large scale deployment of CCS. The Moomba CCS project is an example of the type of projects that the oil and gas industry can undertake in Australia and globally to reduce emissions and create new business opportunities. The project is a CO2 capture, transport and storage project in the Cooper Basin with the aim of delivering material emissions reduction of 1.7 mtpa CO2-e. The project utilises existing and new infrastructure as well as depleted hydrocarbon fields to capture, compress, dehydrate and store CO2 that is currently vented. This study will provide an overview of this project including the technical challenges that were overcome to enable project success.
International standardisation driving global competitiveness and sustainability of the oil and gas and future energy industries
Authors: Keys Matt , Taylor Miranda
Published: July 2021

The World Economic Forum has identified that the oil and gas (O&G) industry must lead the process of its own transformation by innovation and multistakeholder collaboration. The Capital Project Complexity initiative is an industry-wide, noncompetitive collaboration on standardisation and use of procurement specifications. Australia is now a major contributor to this collaboration which has brought together all the major O&G operators through the International Association of Oil & Gas Producers (IOGP) network and the standardisation bodies including International Organization for Standardization (ISO), American Petroleum Institute Standards, European Committee for Standardization, Gulf Cooperation Council Standardization Organization, Standardization Administration of China, Standards Australia (SA) and many more. The focus is on developing common international standards through an IOGP Standards-ISO/TC67 link and standardised equipment specifications linking to these standards through IOGP-JIP33. Australia contributes via SA’s mirror committee ME-92, which is now fully established with direct involvement in the ISO/TC67 9 subcommittee areas and 13 working groups covering 261 current and developing standards. In September 2020, the first of these standards, AS ISO 29001, was identically adopted as an Australian standard. With the Australian experts now ensuring ISO Standards will incorporate Australian industry expertise, knowledge and regulatory requirements where possible future revisions will enable them to be adopted as the next revision of the Australian standard. This industry-wide collaboration will ensure future project costs are optimised and safety enhanced through use of the global industry knowledge while also reducing the need to write local standards. This study describes Australia’s strategy being pursued to align with the global industry. It also provides information on how this network is supporting the development of knowledge transfer to the decommissioning and new energy industries that will form Australia’s future.
Innovation and instrumentation in CO2 monitoring wells for reservoir surveillance and advanced diagnostics
Authors: Barraclough Paul , Bagheri Mohamad , Jenkins Charles , Pevzner Roman , Hann Simon , Wuttke Kelvin , Nikolov Stoyan , Mondanos Michael
Published: July 2021

In 2015, CO2CRC Ltd embarked on an ambitious plan to field test innovative technologies to monitor a CO2 plume injected into a saline aquifer with a view to address many of the economic and environmental concerns frequently associated with commercial carbon capture and storage project’s long-term monitoring programs (Jenkins et al. 2017). It was called the Otway Stage 3 Project and it was focused on testing the technologies of seismic and downhole pressures applied in unique ways to monitor an injected plume of approximately 15000 tonnes as it developed and migrated in the subsurface. To achieve this goal, five new wells were drilled at CO2CRC’s Otway International Test Centre – one dedicated to injection (drilled in 2017) and the remaining four wells (drilled in 2019) were used for monitoring purposes. Each monitoring well and the gas injection well, were outfitted with fibre optic systems installed and cemented outside the casing (specifically for seismic monitoring) and with pressure gauges installed at the reservoir depth. The challenge of the installation was to install fibre optics outside of the casing, cement them in place securely and to perforate the wells without damaging the fragile TEF bundles. While the installation of the pressure gauges in the injection well was a conventional in-tubing gauge mandrel, the installation in the monitoring wells, which were to be used for water injection as well as pressure monitoring, used a less conventional deployment method, where the gauges were instead installed using a more economic and flexible approach by suspending the gauges from the wellhead via a hanger system. This not only ensured continuous offline monitoring of the downhole well pressures and temperatures, but also facilitated future well operations by simple wireline retrieval and deployment of the gauge, forgoing the need for a workover rig. The various systems were commissioned over the period of March–June 2020 and were in full operation in the second half of 2020 – all successfully operating and acquiring baseline data remotely as designed. The Stage 3 Project commenced gas injection operations in December 2020 and data acquisition using the innovative systems have commenced successfully.
Estimating porosity and permeability in the Springbok Sandstone, Surat Basin (Queensland), using new wireline log-based workflow
Authors: Sobczak Kasia , Holl Heinz-Gerd , Garnett Andrew
Published: July 2021

The Upper Jurassic Walloon Coal Measures of the Surat Basin (Queensland) host some of the most prominent coal seam gas (CSG) resources in Australia. The Walloon Coal Measures are directly overlain by the Springbok Sandstone formation, historically referred to as a regional aquifer. An increasing number of studies and industry models suggest relatively limited hydraulic connectivity within the formation and between it and the underlying coal measures, due to extreme lithological heterogeneity. Accurate evaluation of the permeability, as well as lateral and vertical continuity of the lithological units within the Springbok Sandstone, is critical in reservoir models that form the basis of reasonable aquifer protection practices and impact prediction. This study presents a wireline log-based workflow applied to identify permeable zones within the Springbok Sandstone in 31 CSG wells across the Surat Basin that allows robust estimations of porosities and Klinkenberg permeabilities. The workflow primarily utilises spontaneous potential, density, neutron and resistivity logs, and was developed by integrating current industry practices implemented by operators on a local scale to identify risk (permeable) zones in the vicinity of targeted coal seams. The results of this case study indicate that permeable zones within the interval are volumetrically minor (on average 25% N/G) and likely isolated, with Klinkenberg permeabilities rarely exceeding 10–20mD. This evidence for low hydraulic connectivity, as well as significant local variations in the character of the Springbok Sandstone, suggests that the definition of the formation as a regional, continuous aquifer and the way it is modelled needs to be revised.
Fermentative profile and nutritional value of sugarcane silages inoculated with a mixture of fibrolytic enzymes
Authors: Campana Mariana , Carmo Bruno S. , Santos Rafael M. , Garcia Thainá M. , Capucho Estéfani , de Azevedo Eduardo B. , de Morais Jozivaldo P. G. , Del Valle Tiago A.
Published: July 2021

Sugarcane has a high yield potential; however, ensiling has been a challenge, and its fibre has low quality for ruminant feed. This study aimed to evaluate increasing levels of a fibrolytic enzymatic blend (300 U xylanase + 300 U cellulase/g) during sugarcane ensiling on fermentative profile, losses, chemical composition, in vitro degradation, and aerobic stability. Forty silos were assigned to four treatments: 0, 200, 400 and 600 mg enzymatic blend/kg sugarcane fresh matter. The trial was performed in a randomised blocked design, in which five sugarcane cultivars were defined as blocks. Silos were performed in 15-L PVC tubes and stored at room temperature for 45 days. Enzyme level did not affect silage pH, ammonia-N, soluble carbohydrates, ethanol, or organic acid concentration. Although increasing enzyme levels linearly increased effluent losses, there was no effect on gas losses or dry matter recovery. Treatment had no effect on silage chemical composition, in vitro degradation, or silage pH after aerobic exposure. However, enzyme treatment quadratically affected silage temperature after aerobic exposure and aerobic stability period. Intermediate levels of enzymes increased silage temperature after aerobic exposure and reduced the aerobic stability period. Therefore, addition of enzymes during sugarcane ensiling shows no effect on silage fermentation, nutritional value or dry matter recovery, but linearly increases effluent losses. Although an intermediate level of enzymes decreases aerobic stability, it has no effect on silage pH after aerobic exposure.
Cats are a key threatening factor to the survival of local populations of native small mammals in Australia’s tropical savannas: evidence from translocation trials with
Authors: Tuft Katherine , Legge Sarah , Frank Anke S. K. , James Alex I. , May Tegan , Page Ethan , Radford Ian J. , Woinarski John C. Z. , Fisher Alaric , Lawes Michael J. , Gordon Iain J. , Johnson Chris N.
Published: July 2021

Abstract Context Invasive predators are a key threat to biodiversity worldwide. In Australia, feral cats are likely to be responsible for many extinctions of native mammal species in the south and centre of the continent. Aims Here we examine the effect of feral cats on native rodent populations in the second of two translocation experiments. Methods In a wild-to-wild translocation, we introduced pale field rats, Rattus tunneyi, whose populations are declining in the wild, into two pairs of enclosures where accessibility by feral cats was manipulated. Key results Individual rats translocated into enclosures accessible to cats were rapidly extirpated after cats were first detected visiting the enclosures. Rats in the enclosure not exposed to cats were 6.2 times more likely to survive than those exposed to cats. Two individual cats were responsible for the deaths of all but 1 of 18 cat-accessible rats. Rats in the site with denser ground cover persisted better than in the site with more open cover. Conclusions These results are consistent with our previous study of a different native rat species in the same experimental setup, and provide further evidence that, even at low densities, feral cats can drive local populations of small mammals to extinction. Implications Effective feral cat control may be necessary to enable recovery of small mammals.
Loss of function of a DMR6 ortholog in tomato confers broad-spectrum disease resistance
Authors: Thomazella Daniela Paula de Toledo , Seong Kyungyong , Mackelprang Rebecca , Dahlbeck Douglas , Geng Yu , Gill Upinder S. , Qi Tiancong , Pham Julie , Giuseppe Priscila , Lee Clara Youngna , Ortega Arturo , Cho Myeong-Je , Hutton Samuel F. , Staskawicz Brian
Published: July 2021

Significance

Susceptibility (S) genes are plant genes that facilitate pathogen infection. Inactivation of S genes has been considered a promising strategy to obtain broad-spectrum and durable resistance in crops. We characterized two orthologs of the
Arabidopsis
S gene
DMR6
in tomato:
SlDMR6-1
and
SlDMR6-2
. We show that SlDMR6-1, but not SlDMR6-2, is associated with plant immunity. Remarkably,
Sldmr6-1
mutants display enhanced resistance to bacterial, oomycete, and fungal pathogens. This phenotype correlates with increased levels of the defense hormone salicylic acid (SA) and enhanced transcriptional activation of plant immune responses. We also demonstrate that SlDMR6-1 and SlDMR6-2 convert SA into its inactive form, 2,5-DHBA, indicating that they play a role in SA homeostasis.
Matrix lumican endocytosed by immune cells controls receptor ligand trafficking to promote TLR4 and restrict TLR9 in sepsis
Authors: Maiti George , Frikeche Jihane , Lam Carly Yuen-Man , Biswas Asim , Shinde Vishal , Samanovic Marie , Kagan Jonathan C. , Mulligan Mark J. , Chakravarti Shukti
Published: July 2021

Significance

Sepsis is a life-threatening inflammatory disease of dysregulated innate immune cells. Extracellular matrix (ECM) interactions with immune cells are important in this context and require deeper insights. We show that immune cells ingest lumican, a ubiquitous ECM protein produced by fibroblasts, to heighten their response to bacteria but restrict their response to viral or degraded self-DNA released from dead cells. Sepsis patients have elevated circulating lumican, and mice lacking lumican show poor bacterial clearance and resolution of sepsis but elevated response to DNA. Lumican may play a dual protective role in barrier ECM tissues, one of promoting bacterial defense and another of limiting antiviral and autoimmune inflammatory responses.
Inhalable nanocatchers for SARS-CoV-2 inhibition
Authors: Zhang Han , Zhu Wenjun , Jin Qiutong , Pan Feng , Zhu Jiafei , Liu Yanbin , Chen Linfu , Shen Jingjing , Yang Yang , Chen Qian , Liu Zhuang
Published: July 2021

Significance

The recently emerged SARS-CoV-2 variants are more transmissible, which brings new challenges to vaccine treatment. There is an urgent global need for alternative strategies that could effectively and rapidly prevent the infection of various SARS-CoV-2 variants. Herein, we design human angiotensin-converting enzyme II (hACE2)–containing nanocatchers (NCs) derived from genetically engineered cells stably expressing hACE2 as the competitor with host cells for virus binding to protect cells from SARS-CoV-2 infection. An inhalable formulation fabricated by NCs and the mucoadhesive excipient hyaluronic acid could significantly prolong the retention of NCs in the lung and exhibits potent pseudovirus inhibition ability in an hACE2-expressing mouse model. Importantly, the inhalable NCs in the lyophilized formulation allow long-term storage, facilitating their future clinical use.
Ongoing global and regional adaptive evolution of SARS-CoV-2
Authors: Rochman Nash D. , Wolf Yuri I. , Faure Guilhem , Mutz Pascal , Zhang Feng , Koonin Eugene V.
Published: July 2021

Significance

Understanding the ongoing evolution of SARS-CoV-2 is essential to control and ultimately end the pandemic. We analyzed more than 300,000 SARS-CoV-2 genomes available as of January 2021 and demonstrate adaptive evolution of the virus that affects, primarily, multiple sites in the spike and nucleocapsid protein. Selection appears to act on combinations of mutations in these and other SARS-CoV-2 genes. Evolution of the virus is accompanied by ongoing adaptive diversification within and between geographic regions. This diversification could substantially prolong the pandemic and the vaccination campaign, in which variant-specific vaccines are likely to be required.
Chiral dynamics and Zitterbewegung of Weyl quasiparticles in a magnetic field
Authors: Hu Xi-Dan , Li Li-Yan , Guo Zheng-Xin , Li Zhi
Published: July 2021

The relativistic dynamical properties of chiral Weyl quasiparticles (WQPs) are investigated in a stationary magnetic field. The visualized evolution process of quasiparticles’ wavepackets has been calculated with different angles between the spinor and the magnetic field. The results reveal that the chiral WQPs feature anisotropic dynamics, which falls into two typical motion modes, i.e. directional drift (chiral magnetic effect) and periodic oscillation (chiral Zitterbewegung). We theoretically find that the mechanism behind this interesting dynamical phenomenon is the special chiral relativistic Landau level. Since the frequency, amplitude and drift velocity of chiral WQPs can be controlled in a measurable range, one can expect the observation of the phenomenon in the cold atomic system.
Improvements of the programmable quantum current generator for better traceability of electrical current measurements
Authors: Djordjevic Sophie , Behr Ralf , Drung Dietmar , Götz Martin , Poirier Wilfrid
Published: July 2021

A programmable quantum current generator based on the application of Ohm’s law to quantum voltage and resistance standards has demonstrated a realization of the ampere from the elementary charge with a 10−8 relative uncertainty (Brun-Picard et al 2016 Phys. Rev. X 6 041051). Here, we report on improvements of the device leading to a noise reduction of the generated quantized current. The improved quantum current generator is used to calibrate different ammeters with lower measurement uncertainties. Besides, measurements of its quantized current using a calibrated ultrastable low-noise current amplifier have shown that the realizations of the ampere at PTB (Physikalisch-Technische Bundesanstalt) and LNE (Laboratoire national de Métrologie et d’essais) in the range ±50 μA agreed to −3.7 parts in 107 with a combined standard uncertainty of 3.1 parts in 107 (coverage factor k
c = 1).
Comparative analysis of linear electromechanical steering drives with an autonomous hydraulic drive
Authors: Abdulin R R , Bolshakov V V , Podshibnev V A , Rozhnin N B , Samsonovich S L
Published: July 2021

The work is devoted to the topical problem of choosing a scheme of a linear electromechanical drive, developed as an alternative to an autonomous electro-hydraulic drive. Mass characteristics of the main functional elements of the actuators: electric motors and ball screws are considered. Synchronous motors and a collector motors were considered in this work as an electric motor. Ball-screw transmissions with separator and ball-screw transmissions with recirculation of balls were considered in this work as a ball-screw transmission. Comparison was made according to functional, technological and economic criteria of two schemes for construction of linear electromechanical drives: with intermediate mechanical transmission based on a collector motor and based on a permanent magnet synchronous motor without an intermediate mechanical transmission. The comparison showed that the scheme with an intermediate mechanical transmission has better mass characteristics compared to the scheme without an intermediate mechanical transmission with similar dynamic characteristics. The presented comparison results can be useful in solving the problem of choosing schemes for newly developed electric electromechanical steering drives.
Modeling technique for advanced adaptive aircraft catapult devices
Authors: Beklemishchev F S , Tikhonov K M
Published: July 2021

This article represents approaches to the configuration and modeling of adaptive aircraft catapult devices intended for forced separation of aircraft guided missiles from the air vehicle. The creation of such a device is a promising direction of research. The adaptability of such a device lies in the fact that in all air vehicles flight modes, the necessary and safe parameters for separating the air weapons from the carrier are provided. One of the variants of such a device with a hydraulic executive part is considered, its main parameters are determined to meet the requirements for the compartment safety and the possibility of regulating the flow of this process. The computer modeling technique is based on the use of approved information technologies SolidWorks, SimInTech and EULER, which allow solving multiphysics tasks, as well as reducing the full-scale experiments volume due to their use. As a result of comparing the results of mathematical modeling and experimental studies, it was found that the model of the adaptive aircraft catapult devices, developed on the basis of the methodology, describes the processes of payload movement fairly accurately.
Bird colony algorithm use in the logistics module of the production management system
Authors: Belousov I A , Firsov K I
Published: July 2021

The report discusses the application of the bird colony algorithm together with the solution of the clustering problem in the logistics module of the ERP-system. This polynomial algorithm belongs to the category of stochastic biotic algorithms. The main rule of the implementation of the bird colony algorithm is that the so-called swarm intelligence is used to solve the optimization problem. The article describes the rule of algorithm operation, the study of the properties of this algorithm based on the results of modeling on a real base of target points and makes a comparative analysis of the algorithm with previously used algorithms in the system. The application of the algorithm in matrix form using the entropy matrix is described in the report. The obtained results allow us to say with confidence that the use of the bird colony algorithm can significantly increase the algorithm speed of logistic module.
Non-parametric tuning of PID Controllers: Evolution of ideas
Authors: Boiko Igor
Published: July 2021

Non-parametric tuning was introduces by J. Ziegler and N. Nichols with the step test and continuous cycling tests and the respective tuning rules. Whereas the step test based tuning had some feature of parametric tuning, the continuous cycling test based tuning was purely non-parametric. The latter test involves bringing the system under proportional control into a sustained oscillation and measuring the frequency of these oscillations and fixing the gain value, that are called the ultimate frequency and ultimate gain. The test was intended for manual tuning of PID controllers. It is relatively hard to automate, and it is not used in auto-tuners. Another test, called relay feedback test (RFT), was proposed by K. Astrom and T. Hagglund to excite self-oscillations through the inclusion of a nonlinear element (relay) in the control loop. This test is easier to automate, and it found applications in industrial auto-tuners. In both these tests ultimate frequency coincides with the phase cross-over frequency of the process/plant. Yet, both the original continuous cycling test and the RFT suffer from such a drawback as the change of the phase cross-over frequency after PID controller introduction. A new test, the modified relay feedback test (MRFT), which can ensure that the test oscillations are excited at he frequency that becomes the phase cross-over frequency after introduction of a controller in the loop, was recently introduced. This property is attained throughcoordinated test and tuning, which is considered in the book chapter. Moreover, the tuning rules are optimized for a selected class of processes, which offers the paradigm ofoptimal non-parametric tuning.
Public transport synchronization problem and the possibility of its compliance with social distances on the example of regional airport hubs
Authors: Borodavkin V A , Kapitonov Yu A
Published: July 2021

The problem of organizing passenger transfers at regional airport hubs in terms of the pandemics is considered in the article. On the one hand, public transport has become a dangerous place for the spread of diseases. On the other hand, it is necessary for the existence of key sectors of the economy. A mathematical model of the synchronization of the arrival and departure of aircraft is proposed as the assignment problem. Unlike other available models, the goal is to slow down the speed of passenger flows with the ability to maintain social distance in the area of the transfer airport. The proposed model has a fan pattern schedule scheme, in which, until a certain estimated time, only arrival of vehicles is carried out and after this estimated time only departure. Aviation regional interchange hubs located in the Siberian part of the Russian Federation were considered in numerical experiments. To detail the restrictions, the service regulations for transit flights on domestic airlines were used. Thus, it is proposed to implement one of the concepts of transport operation in a pandemic, especially to abandon the speed as a service in favor of passengers’ safety.
Game control of air strikes against a recoverable ground facility
Authors: Bukhalev V A , Boldinov V A , Skrynnikov A A
Published: July 2021

The current task is dedicated to the problem of developing minimax game control in pure strategies when two enemies (an aviation group and a repair team) act against each other. The first one destroys an object and the second one repairs it. The algorithm of optimal controlling process based on the average risk criterion does not guarantee a result of the governance. It happens because of both enemies observe and conduct the object’s structure. Optimal solutions are based on the Systems theory with a random jumping structure and the Game theory too. The controlled object is described by dynamic stochastic system with a random jumping structure which has a finite number of possible states. Transitions from one state to another occur at random moments of time and they are controlled by two warring parties (the aviation group and the repair team) pursuing strictly opposite goals. State changing process of the object’s structure is assessed by indicators of players which are worked with errors. Some kind of object’s state functionality is a criterion for the optimality of controlling processes. One party seeks to minimize it and the other one seeks to maximize it. Players control the object’s structure in clean strategies applying the final number of possible strategies. The optimal controlling processes are among the class of non-stochastic mathematical dependencies on the observations results which are preceded the current moment.
Overview of automation tools for avionics verification
Authors: Dyachenko S A , Ilyashenko D M , Neretin E S
Published: July 2021

The existing verification automation tools for civil aircraft avionics are considered (particularly, formal methods, hardware-in-the-loop testing, outsource sendees). Key solutions presented on the market are described, their advantages and weak points are identified. Also, it is determined a promising field is the automation of graphic and aural information testing during the cockpit human-machine interface assessment (e.g. for cockpit display and flight warning systems). This type of verification is practically not automated nowadays. The architecture of a complex for the mentioned task is proposed, the methodology of verification using the described tool is considered either. The camera and microphone usage for monitoring of images and sound alerts which is being outputted to the crew allows applying of computer recognition algorithms during verification. It will allow reducing the time and cost expenses for human-machine interface testing as well as reducing the probability of mistakes could be made during fully manual testing. In addition, the proposed concept makes its application possible for any technical objects with a user interface in other industry areas (not just in aviation) such as space, automotive, shipbuilding, etc.
Development of a distributed microprocessor control system for the 6 degree of freedom motion simulator
Authors: Efromeev A G , Goryachev O V , Morozov O O
Published: July 2021

The article deals with the design issues of a microprocessor control system for the 6 degrees of freedom motion simulator. This motion simulator is a high performance, electro-pneumatic simulator, used for test evaluation of small high dynamic flying objects. With pneumatic actuated yaw and pitch axes and an electric motor on the roll axis, the Motion simulator reproduce, in real-time, the flight motions of the actual object. The presence of a large number of servo drives with different types of executive elements in the Motion simulator required the development of a distributed multiprocessor control system. The equipment of the Motion simulator includes a number of microprocessor control units. Each contains a microprocessor control system with high-performance microcontroller having specialized peripherals, as well as equipped with all the necessary communication interfaces. Control units are maximally unified, which significantly reduces the time of their development and debugging. Due to this, units firmware is mostly identical and uses the same set of libraries.
Synthesis of an algorithm for controlling an electric servo drive with a hybrid stepper motor
Authors: Goryachev O V , Stepochkin A O
Published: July 2021

One of the promising directions in the development of an electric servo drive systems is the use of a hybrid stepper motor without a rotor position sensor in precise positioning systems. A procedure for synthesizing an algorithm for controlling an electric servo drive based on a hybrid stepper motor is considered. A method is proposed for switching the windings of an operating motor, which makes it possible to exclude resonance phenomena in the drive power system. An algorithm for vector control of the torque of a stepper motor is developed using the algorithm for observing the speed and angle of rotation. A simulation model of the electric servo drive with vector control and adaptive speed observer has been developed in the package Simulink. The effectiveness of the proposed methods for controlling the operating motor is confirmed by the results of dynamic modeling.
Expert assessment of the cockpit crew information and control field
Authors: Greshnikov I I , Salnikov T D , Ivanov A S
Published: July 2021

This paper discusses the method of expert assessment based on the probabilistic approach of the paired comparisons method. This mathematical apparatus is the basis for special software integrated into the universal stand for prototyping the cockpit, which allows for a systematic expert assessment at this stand according to pre-selected criteria with the control of the consistency of the answers. Using this method, the task of determining the feasibility of displaying layers of synthetic and enhanced vision on the flying frame is solved, but in general, the method allows evaluating any elements of the displays and controls.
Movement of a group of unmanned aerial vehicles in formation
Authors: Heiss E A
Published: July 2021

This paper presents a method for organising the movement of unmanned aerial vehicles in formation. In the presented method of UAV collisions are prevented by a modification of the potential field method. The movement of the group is accomplished by incrementing the origin coordinates of the formation at each iteration of data exchange between UAVs. This paper presents a graph showing the negligible positioning error of drones in formation over time as the heterogeneous swarm of quadcopters moves towards the target position. Simulation results show that the flight time of a group of UAVs to the target swarm position using the proposed method is longer than using the master-slave method. The model of a Wi-Fi network as an information exchange network between UAVs was used in the developed simulation environment. This approach facilitates the implementation of the presented method on real aircrafts.
Software package for simulating a group of unmanned aerial vehicles performance
Authors: Kim R V , Frolova D V , Borovkov A S
Published: July 2021

The paper presents the architecture of a software, designed to simulate the functioning of a group of unmanned aerial vehicles. The software consists of two components: software for modeling unmanned aerial vehicles functioning processes, which designed to simulate the controlled movement of a single UAV and to simulate the functioning of its onboard systems and software for the ground control post, which designed to form a flight task, generate and send control commands to the UAV, and receive information from the UAV about its current state. The paper also discusses the unmanned aerial vehicle group application scenario, main functions of each software components, its user interface as well as implemented models and algorithms.
Formation and research of UAV safety models and observability of objects when monitoring the fire setting
Authors: Kozorez D A , Mokrova M I , Kim N V
Published: July 2021

Fire monitoring with the use of an unmanned aerial vehicle is a two-criterion task, since there is a need to maximize the vehicle protection against the thermal influence of the fire, as well as to increase the observability as much as possible achieved by reducing the flight height. This paper contains empirical models, representing the flight safety of an unmanned aerial vehicle and the observability of the target objects during fire situation monitoring. The proposed models allow to consider the peculiarities of the monitoring conditions., using a car as a sample target. The analysis of the proposed models is carried out, and the relevant quantitative results are provided. The work defines the criteria for the selection of an optimum aerial vehicle flight height over the area under surveillance, and they are generated, using an expert assessment database.
Time response analysis for two-phase PMSM with two-sectional phase windings
Authors: Krivilev A V , Dunich E A
Published: July 2021

A new approach to investigation of two-phase PMSM control methods on the level of phase windings sections is presented. For two-phase PMSM with two-sectional windings all control methods are considered from a unified position. Section and phase usage variants implementable at all possible section connection schemes are determined and classified; armature magnetic induction vector amplitudes and angle positions are calculated. The vectors are grouped by graphical representation, phase usage variant and section connection scheme into sets, number of which leading to non-zero vectors and the zero vector is determined. A simulation is carried out, speed time response curves are calculated and compared; the affecting of section connection scheme and phase usage variant on speed transition time and idle speed is ascertained; groups are discovered, section connection schemes can be attributed to. The obtained results can be used in demand by drive developers to select the most suitable PMSM control method.
Decision support system HMI for the problem of four-dimensional navigation in civil aviation
Authors: Neretin E S , Budkov A S , Ivanov A S
Published: July 2021

The work is devoted to the development of a human-machine interface (HMI) of the decision support system for the problem of four-dimensional navigation. As part of the work, the analysis of the functionality of modern flight management systems, which is designed to solve the problem of four-dimensional navigation, was carried out. The problems that arise during flights along the four-dimensional navigation routes are determined, and the insufficiency of the existing functionality of modern flight management systems for solving these problems is substantiated. The paper proposes the functionality of the decision support system as an addition to the functionality of the flight management systems, as well as the organization of the HMI of the decision support system, which provides display of the necessary information for the decision-making process by the crew.