bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring of Organizational, Technological and Environmental Solutions in Construction with Blockchain Technologies
Authors: Abramyan S G , Klenina E A , Peskov A E , Burlachenko A O
Published: March 2021

The paper considers the relevance of blockchain technology in the field of construction, highlighting that the expansion of information modelling through integration of BIM and blockchain technology opens up new opportunities not only for making beneficial construction agreements, but also for arranging comprehensive monitoring of construction progress. It also argues that the number of blockchains depends on the selected option of devising organizational and technological solutions for any type of construction. The paper offers an example of a specific project with a brief description of the construction technology employed therein and provides an interconnection diagram of organizational, technological and environmental blockchains. Novelty of the paper consists in the fact that it suggests considering technology and work organization blockchains as elements inseparable from environmental blockchains. The theoretic importance of the work stems from the fact that it may serve as the basis for developing the theory and general methodology for creating construction blockchain technology and its integration with BIM technology.
Influence of Ni / NiO Ratio on the Performance of Thermoelectrochemical Waste Heat Harvester Based on Hollow Microspheres
Authors: Boychenko E A , Kiselev N V , Taganova A A , Artyukhov D I , Khaidarov B B , Kolesnikov E A , Yudin A G , Vikulova M A , Gorshkov N V , Kuznetsov D V , Burmistrov I N
Published: March 2021

Technologies harvesting and converting the heat of low-temperature sources into electricity are one of the current trends in modern renewable energy. Thermoelectrochemical cells based on a nickel oxide electrode are gaining increasing popularity among researchers due to the high values of the hypothetical Seebeck coefficient. This work is devoted to the study of the reduction modes effect of hollow nickel oxide microspheres on the ratio of oxide and metal nickel forms in their structure. The paper presents the synthesis of microspheres by the pyrolysis of ultrasonic aerosols of an aqueous solution of nickel nitrate. Composition and morphology are studied by scanning electron microscopy and X-ray non-standard quantitative analysis. It was shown that the proportion of metallic nickel increases with an increase in the reduction temperature to about 375°C and then changes slightly. For microspheres, reduced at 350 °C, the main parameters of the thermoelectrochemical cell were determined. It was shown that the hypothetical Seebeck coefficient in the assembled cell system is 3.1 mV/K, and the resistance to charge transfer across the electrode-electrolyte interface was less than 1 Ohm. It confirms the applicability of these materials as electrodes for electrochemical systems and the possibility of obtaining high values of output power.
Diagnosing the Most Effective Environmental Aspects in Eco-Friendly Multi-Storey Residential Complexes
Authors: Alawsi W A , Molchanov V M , Shahin B R
Published: March 2021

The global evaluation systems based on the specialized environmental aspects are the most widespread around the world. The ratings of these systems depend on the type of projects to be evaluated and, moreover, on the specifics of the area. In this paper research the author intends to review and analyse the most important terms and indicators of these systems to build the basis for selection and inclusion of the key effective aspects. The purpose of these effective aspects is to improve the environmental performance of eco-friendly residential complexes. The author abstracted and clearly identified six effective environmental aspects furthermore, minor aspects are also implied, and all of them constitute an approved basis for evaluating the performance of environmentally friendly multi-storey residential complexes.
Ways to Eliminate Unpleasant Smelling Substances for the Environmental Safety of Meat Industry Enterprises
Authors: Svetlov D A , Svetlov D D , Belousova N I , Lisitsyn B A , Erofeeva I V , Dergunova A V
Published: March 2021

A lot of attention is being paid to the issues of safe stay of humans and other biological communities in residential and working premises, industrial and agricultural buildings. This is due to the fact that microscopic organisms, along with the destruction of building materials and products in buildings, can cause a pathological condition called Sick Room Syndrome (SBP), allergies, and sometimes mycotic infection of the lungs. In this paper, we consider the issues of improving the environmental situation in buildings of meat processing plants, by reducing the emissions of unpleasant-smelling substances in the air of the working area with the help of disinfectants “Teflex”. The bactericidal effect of the drug “Teflex” is determined by the ability of guanidine derivatives to bind to the cell walls and membranes of bacteria, penetrate into the cell nucleus and inhibit cellular enzymes. The technology of treatment of premises with a solution of disinfectant using a “quasar” type sprayer and a “Clean air” installation is presented. It was experimentally revealed that in this case it is advisable to use 1,5-2,0 % solutions of the disinfectant. The use of disinfectants in such concentrations helps to eliminate unpleasant-smelling substance as a continuous source of emission, and the presence of volley emissions.
Integrated Sustainable Development of Small Towns and Settlements
Authors: Shalina D S , Stepanova N R , Drozdova A V
Published: March 2021

When we develop big cities, we forget about small cities and settlements. The rate of development of small towns is very low. You can change the trend of improvement and prosperity: direct efforts to the development of small towns. In our research, we consider the village of Shalya. It has a lot of potential, but it needs a push. After a survey of the population and our research analysis, we have chosen a certain territory and directions for its integrated sustainable development. As a result, we justified our project in terms of marketing and economic aspects. The new facility with elements of digitalization in Shalya will contribute to the development of the city and the use of similar technologies. Citizens’ lives will improve.
To the Question of the Influence of the Polar Region Seismicity on the Ground Transportation Infrastructure
Authors: Makhutov N A , Kossov V S , Lunin A A , Oganyan E S , Shabunevich V I
Published: March 2021

A harmonic analysis is carried out for a simplified finite element model of the Earth with characteristic important elements of transportation infrastructure in the equatorial and polar regions. The results are presented for the calculation of the Earth model with the sections of the main pipelines attached in the specified areas, as well as the results of a similar calculation for the assembled rails and sleepers with the embankment and basements with different properties under harmonic displacements of the basements. The calculations show significantly greater load on the considered elements of the transportation infrastructure in the polar region as compared to the equatorial one because the displacements of the Earth’s surface in the polar zones of the model are much greater in magnitude than in the equatorial ones. Consequently, it is necessary to consider these phenomena in the calculations and experimental measurements of seismic impacts when designing transportation infrastructure in the Arctic region.
Strength Analysis of Concrete-Filled Steel Tubes on the Basis of Plasticity Conditions
Authors: Pavlikov A M , Kochkarov D V , Harkava O V
Published: March 2021

The methods of calculating the strength of concrete-filled steel tubular members based on the theories of plasticity of Saint-Venan and Huber-Mises-Genka are developed in the article. The criterion for the destruction of the composite element is the ultimate limit state. The strength of the normal cross-section of a cylindrical concrete-filled steel member at axial compression is determined taking into account the meridional pressure of the concrete on the tube and axial stress in it. The equation of strength of the tubular member is obtained, in which the stress in the tube reaches the design yield strength of steel at the moment of destruction of the element, that is, the strength of the materials is used completely. An example of the calculation is performed and the results of the calculation is compared with the experimental data for 13 samples.
Comparison of the Durability of Buildings in a Group
Authors: Shafranovsky T , Rimshin V , Varlamov A , Merkulov S
Published: March 2021

The influence of various factors on the durability of concrete and reinforced concrete structures is determined. Three groups of factors are identified: elasticity, strength, and crack resistance, which influence the assessment of the durability of reinforced concrete. Based on the analysis, the determining influence of the crack resistance factor on the degradation of concrete was revealed. Based on the analysis of existing methods for determining the characteristics of concrete crack resistance, a new method is proposed. The method allows us to evaluate the crack resistance (fracture toughness) of concrete and reinforced concrete structures in any state. The method is proposed and the description of samples for the implementation of the method is given. Standard formulas based on prismatic samples extracted from concrete were used to evaluate the crack resistance characteristics. Comparative tests of samples were carried out using the known and proposed method. The obtained characteristics are used to assess the condition and durability of structures of buildings and structures.
Development of an Analytical and Graphic Method for Determining the Compositions of Epoxy Compounds with Increased Chemical and Biological Resistance
Authors: Gavrilov M A , Gubanov D A , Martynov A A , Filatov A V
Published: March 2021

The task of developing durable and effective building materials for protection against aggressive environments is urgent. One of the ways to increase the durability of buildings and structures is the use of polymer composite materials during their construction. In addition, the urgent task of recycling waste from construction and chemical industries also has to be considered. Determination of rational compositions of composite materials manufactured by compression and vibrocompression methods is of considerable interest. The problems of obtaining compositions of polymer composites based on the use of a modifying additive - a plasticizer (organosilicon varnish KO-922) and asbestos-containing fillers based on waste from construction and chemical industries are addressed. An analytical and graphical method for calculating the compositions of epoxy composite materials based on production wastes has been developed. Rational formulations based on modified epoxy binder have been obtained. The nomograms make it possible to make a practical choice of one or another filler composition for given conditions.
The Technology of Installation Using Pneumatic Inflatable Formwork
Authors: Abu-Khasan M , Egorov V , Nikonova E , Sakharova A
Published: March 2021

The article is devoted to the current topic of fast-assembled buildings, the analysis of existing technologies, including the use of pneumatic formwork, allows installation both in the urban environment and in special conditions. A crane-free installation technology using pneumatic formwork is proposed, followed by filling the inter-deck space with foam material based on Quad Core.
Optimization of the Configuration of Cross-Beam System Dimensional Structure Depending on the Specified
Authors: Abu-Khasan M , Egorov V , Perminova T , Abu Khasan P
Published: March 2021

This article presents an analysis of cross-beam systems made of wood-composite materials made of glued wood, highlights their positive aspects, including a significant reduction in the weight of the structure, as well as disadvantages that prevent the spread of this technology in Russia. The experience of calculation and construction of structural plates in Russia is considered. the most progressive method of arrangement of the core structure is determined experimentally. The possibilities of using cross-beam systems for the construction of public buildings and structures are considered.
Verification of the Method for Constructing Computational Models of Hybrid Beams in Software and Computer Systems that Use the Finite Element Method as Their Basis
Authors: Egorov V , Abu-Khasan M , Mamyrova A
Published: March 2021

To analyze the operation of hybrid structures, it is necessary to build their models with subsequent calculation in special computational software systems that use the finite element method as their basis. One of the features of hybrid structures is the use of dissimilar materials in a single structure, arranged in a special way, ensuring their joint work. When creating a calculation model of a hybrid beam in PVC, it is required to take this feature into account and pay special attention to the contact areas of dissimilar materials. The article analyzes 2 methods for creating computational models in the SCAD, taking into account this feature, verification of the results obtained. Conclusions are drawn about the possibility of using these methods in design.
Technological Schemes for Collection, Disposal and Treatment of Surface Run-off and Their Development
Authors: Strelkov A K , Teplykh S Yu , Gorshkalev P A
Published: March 2021

The paper focuses on surface wastewater collection and its disposal from railway station tracks. It is described that usually either drainage trays located along the tracks or perforated pipelines arranged in special channels filled with water-permeable material are used to collect and divert surface run-off from the railway track. The analysis reveals the qualitative and quantitative composition of surface run-off. The paper shares data obtained during the investigation of railway stations and enterprises of the Kuibyshev railway and focuses on contamination of the territory of this enterprise with petroleum products and on concentrations surface wastewater contamination with petroleum products, suspended substances and iron. The authors further introduce technological schemes for surface wastewater treatment, which allow achieving the quality of treated wastewater at the level of maximum permissible concentrations for water bodies of fishing purposes.
Management of Integrated Utilization of Industrial Waste Storage Facilities
Authors: Tumenova S A
Published: March 2021

Absract. At the current stage of development, access to mineral resources is becoming a critical factor in economic growth, which requires an increase in the use of both natural and technogenic raw materials. The article is dedicated to the management of industrial waste. An algorithm has been developed for the recycling system for technogenic deposits, which can serve as a methodological basis for strategic management of the process of involving them in the economy. An organizational and management model of a private eco-industrial park of the Greenfield type is proposed as an integrated system aimed at the use of technogenic resources, as well as environmental rehabilitation of waste localization sites. The possibility of its application for the processing of stale tailings of the former Tyrnyauz tungsten-molybdenum plant is estimated. It is concluded that, as a result of the integrated use of the unique resource potential of the waste accumulators of this mining and processing plant, the formation of prerequisites for its restoration is possible.
Efficiency Increase of Sowing Complexes
Authors: Redreev G V , Kachurin V V , Myalo O V
Published: March 2021

The sowing combined machine-tractor units and complexes have a great potential for productivity. However, in practice, the potential implementation remains at the level of 45-55%. The reason for this is the low reliability of agricultural machines that are part of the units. At the same time, the high cost of complexes causes it to belong to large agricultural associations and holdings that have significant acreage and correspondingly long distances to repair and maintenance facilities. In this case, the task of ensuring the required level of reliability of sowing complexes can be successfully solved by mobile service units. To do this, it is necessary to determine the causes of downtime of sowing units and complexes and set the optimal values for the parameters of the processes of using the units and restoring its operability. The reasons for downtime of aggregates were established by time-based monitoring in several agricultural holdings in the Chelyabinsk region. The controlled seed aggregates and complexes were divided into three groups according to the degree of realization of its productivity potential. For each group of units, the qualitative and quantitative parameters of spare parts stocks of agricultural machines were determined; modes of operation of mobile units for maintenance and repair of crop complexes, elimination of its malfunctions and breakdowns, assistance to drivers of units in eliminating the consequences of failures. The measures are proposed to reduce downtime of sowing complexes for organizational and other reasons. This made it possible to increase the degree of realization of the potential of sowing units and complexes.
Industrial Production of Acetal-Based Corrosion Inhibitors
Authors: Gabitov A I
Published: March 2021

Summary of researching results of practical application of 1,3-diheterocycloalkanes as new highly-efficient corrosion inhibitors is presented herein, made by Ufa State Petroleum Technological University and Research Institute of Fine Chemicals and Agents headed by Professor D. L. Rakhmankulov. The relevance of the problem studied is stipulated by possibilities in application of petrochemical intermediate products and waste to get multifunctional corrosion inhibitors. Researching of corrosion inhibitors with the use of acetals is demonstrated to be made in two directions: tailor-made synthesis of corrosion inhibitors of acetal type using cheap and available petrochemical stock; making corrosion inhibitors with increased protection properties and improved processing quality by blending with other substances. Under the pilot studies the process flow diagram for making industrial synthesis is proposed, and efficient operating conditions for the reaction enabling to get the best results to increase the output of the desired condensate (i.e. efficient corrosion inhibitors) are defined. Standard processing unit for making corrosion inhibitors by blending is engineered and proposed to be implemented and that was installed in some enterprises of the Republic of Bashkortostan.
The Contemporary State of Reforestation in the Territory of the State Forest Fund of the Primorsky Region
Authors: Prikhodko O Yu , Bychkova T A , Pretsiniek I P
Published: March 2021

Primorsky Krai is a region unique in its biological diversity. However, the state of the forest fund of the region over the past 70 years has significantly changed because of unsystematic logging and forest fires. There is a special attitude towards forest restoration in the region. First of all, there is an opinion that artificial forest regeneration in Primorye is not effectually, because of the natural conditions witch allow the forest to grow well itself. The prevalence of naturally regenerated stands in the areas of the state forest fund is a result. However, the reforesting reserves in the region attends significant areas, agro technical care is required in large quantities, mono breed reforestation can not be used everywhere and natural regeneration by economically valuable species is possible after a long period of forest cultivation. To analyse what has been done and planned for the future we can by studying the forest plan of the subject and reports on its implementation, which we tried to do in this work.
Occupational Risk Assessment for Workers of Aluminum Production Using the Example of RUSAL Bratsk OJSC
Authors: Murzin M A , Tepina M S , Gorlenko N V
Published: March 2021

Aluminum is considered one of the most commonly used materials and has a wide range of applications in various industries. However, the production of aluminum is associated with a significant negative impact on the health of workers engaged in technological operations to produce it. In this regard, the aim of the work was to assess the occupational risks of workers in aluminum production. As a result of the analysis, it was found that the technological process for producing aluminum has a complex of negative effects on the health of workers, which includes industrial noise, general and local vibration, gas and dust contamination of the air in the working area, exposure to electromagnetic fields and radiation, adverse microclimate parameters. The totality of dangerous and harmful factors in working conditions and negative indicators of injuries and occupational morbidity for aluminum production workers requires carrying out a procedure for assessing occupational risks. Of the whole set of methods, we selected the three most informative and easy to use methods, i.e. the method of scoring occupational risks, the method of assessing the IOR level and the Fine-Kinney method. The object of the study was RUSAL Bratsk Aluminum Smelter OJSC. Based on the results of the assessment, it was established that the general level of occupational risk in RUSAL Bratsk OJSC corresponded to the “medium” and “high” values of these methods, which is considered unacceptable. To reduce the risk, it is necessary, in particular, to implement additional or modernize existing labor protection measures.
Building a Nomogram to Determine Drilling & Blasting Parameters in the Marginal Quarry Zone
Authors: Zharikov S N , Kutuev V A
Published: March 2021

In the paper, blasting seismic survey results for some mine blocks are given. Issues of studying the wave propagation processes in the rock mass and solutions to them are described specifically for mining engineers with minor theoretical deviations and emphasizing maximum practical significance. The method developed by the Mining Institute of the Russian Academy of Sciences Ural Branch to determine protective measures against the effects of blasting on protected objects depending on the explosive weight in delay, soil factors, and the permissible seismic velocity is described.

Based on previously identified patterns for various soils, dependencies between the rock mass properties and charge parameters have been built and summarized in a nomogram to simplify the corresponding determination of the technical explosion parameters. The advantage of this approach, in contrast to others, is the possibility of a quick multivariate evaluation, which is of great importance for the prompt elaboration of technical solutions.

In the paper, the specifics of determining the drilling & blasting parameters when approaching the marginal quarry zone are partially discovered and promising areas in studying seismic phenomena in rocks and the blast seismic for the nearest future outlined.
Ecological Consequences of the Intensification of Agricultural Production and Land and Agrarian Reforms (Based on Materials from the Altai Territory)
Authors: Voronkova O Y , Kovaleva I V
Published: March 2021

Altai Krai is traditionally classified as a major industrial and agricultural regions of the country. The machine-building complex (production of tractors, agricultural machinery, wagons, engines, boilers), the chemical and petrochemical industries (tires, artificial fibers, plastic products, chemical products), the food industry (meat, cheese making), and the light industry (manufacturing) are quite developed. fabrics, knitwear), mining (mining of polymetallic ores, gold, table and glauber salts, coal). Agriculture prevails in agriculture in the Altai Territory. Altai Territory is one of the largest producers of grain, milk, meat and other agricultural products. The territorial specialization of agricultural production in the region is determined by the complex mechanism of interaction of natural and climatic factors, as well as soil and geomorphological features. Among cultivated crops, cereals prevail. Hard and strong varieties of zoned spring wheat are grown in the most provided warm steppe part of the territory of the region.

Altai Krai is the only region beyond the Ural Mountains where sugar beets are grown. Among oilseeds, the lion’s share is occupied by sunflower, although commodity production of oilseed flax, mezeum, long flax, rapeseed and other industrial crops is gradually developing.
Mechanical Activation, Mineral Powders, Chemical Modification, Solid-Phase Reactivity, Polyorganosiloxanes
Authors: Vavrenyuk S V , Efimenko Yu V , Vavrenyuk V G
Published: March 2021

Mechanochemical reactivity of nonfunctional organosilicon polymers with the most typical structure (linear, cyclolinear, three-dimensional) was studied: polyphenylsiloxane (PPS), polyvinylsiloxane (PVS), polydimethylsiloxane liquid (PMS-6) and dimethylsiloxane rubber (SKTN).
XXL Format in Light Graphity the Design of the City Environment
Authors: Maltseva E A , Piirainen V Yu
Published: March 2021

This article discusses XXL graffiti format (mural), classification. The author describes the execution of graffiti format XXL on the facade of buildings, technical features. The main functional aspects of graffiti –mural in the urban environment are identified and analyzed: navigation, lighting, communication. Considerable attention is paid to the first international festival “The Best City of the Earth” in Moscow, where about 150 city walls were painted. In conclusion, it is stated that building owners, architects and urban planners use graffiti to transform abandoned industrial zones, multi-storey residential areas into open-air art galleries and simultaneously change the negative image of urban areas.
Basic study of mobile gamma ray imaging using a digital camera and scintillator
Authors: Yoshitani Hiroshi , Fujibuchi Toshioh , Nakajima Yumiko
Published: March 2021

Gamma cameras are used in nuclear medicine examinations involving radioisotopes; however, they do not provide real-time feedback. We propose a real-time imaging method based on a commercially available digital camera and a scintillator array to provide simple and accurate measurements of radioisotope accumulation and contamination. We evaluate the sensitivity and resolution of the proposed device using x-rays as a proxy for gamma-rays. The performance of the device is demonstrated using PENTAX KP and ORCA-spark C11440-36U digital cameras. A caesium iodide scintillator array is irradiated with x-rays, with the state of light emission confirmed using live view images. The pixel value is evaluated as a function of dose rate. Furthermore, we investigate the state of light emission in response to amplifying the light signal using an image intensifier. For the PENTAX KP, luminescence is observable for a dose rate of approximately 10 mSv h−1, which changes to 2.1 mSv h−1 when an image intensifier is used. Notably, the ORCA-spark detected emission at a low dose rate of 0.06 mSv h−1. However, using an image intensifier resulted in noisier images. Therefore, although the ORCA-spark can observe luminescence at a suitable predicted dose rate for application in nuclear medicine examinations, a collimator is required to control the spread of gamma rays. However, as this causes the sensitivity to decrease, increasing the amount of light emitted by the scintillator and improving the sensitivity of the camera is vital.
Laser-defined graphene strain sensor directly fabricated on 3D-printed structure
Authors: Aga Roberto S , Webb Tyler M , Pandhi Twinkle , Aga Rachel , Estrada David , Burzynski Katherine M , Bartsch Carrie M , Heckman Emily M
Published: March 2021

A direct-write method to fabricate a strain sensor directly on a structure of interest is reported. In this method, a commercial graphene ink is printed as a square patch (6 mm square) on the structure. The patch is dried at 100 °C for 30 min to remove residual solvents but the printed graphene remains in an insulative state. By scanning a focused laser (830 nm, 100 mW), the graphene becomes electrically conductive and exhibits a piezoresistive effect and a low temperature coefficient of resistance of −0.0006 °C−1. Using this approach, the laser defines a strain sensor pattern on the printed graphene patch. To demonstrate the method, a strain sensor was directly fabricated on a 3D-printed test coupon made of ULTEM 9085 thermoplastic. The sensor exhibits a gauge factor of 3.58, which is significantly higher than that of commercial foil strain gauges made of constantan. This method is an attractive alternative when commercial strain sensors are difficult to employ due to the high porosity and surface roughness of the material structure under test.
Comment on ‘Analytical study of heat and mass transfer in MHD flow of chemically reactive and thermally radiative Casson nanofluid over an inclined stretching cylinder’
Authors: Awad M M
Published: March 2021

Correction to the Rd expression is given so that the Rd is multiplied by 4/3 in the Nux expression. Also, corrections to the τ
w and qw expressions are given so that the τ
w and qw units are kg m−1 s−2 and W m−2 respectively.
US industrial sector decoupling of energy use and greenhouse gas emissions under COVID: durability and decarbonization
Authors: Miller Sabbie A , Grubert Emily
Published: March 2021

The 2020 response to the coronavirus pandemic has had a profound and rapid effect on social behavior, the economy, and consumption. Associated declines in greenhouse gas (GHG) emissions have prompted calls to action to use the pandemic experience to accelerate decarbonization. Such action depends on understanding how GHG emissions reductions were achieved and whether they can be sustained. In this work, we focus on the industrial sector by comparing United States (US) industrial energy consumption, CO2 emissions, and key materials production between the first two quarters (Q1 and Q2) of 2020, when pandemic response became active, relative to 2019. We show a striking decoupling between energy use and GHG emissions in the US industrial sector between Q2 2020 and Q2 2019, yet pandemic decarbonization in the industrial sector is unlikely to be durable. Observations suggest three major takeaways for US industrial decarbonization: (1) efforts to decarbonize transportation will contribute to industrial decarbonization due to the large impacts of petroleum refining; (2) increasing demands for materials that use energy resources as feedstocks (e.g., plastics) can result in an apparent decoupling in energy demand and GHG emissions that is not indicative of a durable pathway for reducing GHG emissions; and (3) temporary reduction in demand for industrial infrastructure materials would have resulted in greater reductions of GHG emissions than the relative change in fuels used during this period. Cumulatively, while shifts that would lower GHG emissions occurred, no substantial structural changes to industrial activity were observed. As such, society still requires systemic change to interdependencies on other sectors and the methods we use to produce and deploy our industrial materials.
Topological and geometrical aspects of band theory
Authors: Cayssol J , Fuchs J N
Published: March 2021

This paper provides a pedagogical introduction to recent developments in geometrical and topological band theory following the discovery of graphene and topological insulators. Amusingly, many of these developments have a connection to contributions in high-energy physics by Dirac. The review starts by a presentation of the Dirac magnetic monopole, goes on with the Berry phase in a two-level system and the geometrical/topological band theory for Bloch electrons in crystals. Next, specific examples of tight-binding models giving rise to lattice versions of the Dirac equation in various space dimension are presented: in 1D (Su–Schrieffer–Heeger (SSH) and Rice–Mele models), 2D (graphene, boron nitride, Haldane model) and 3D (Weyl semi-metals). The focus is on topological insulators and topological semi-metals. The latter have a Fermi surface that is characterized as a topological defect. For topological insulators, the two alternative view points of twisted fiber bundles and of topological textures are developed. The minimal mathematical background in topology (essentially on homotopy groups and fiber bundles) is provided when needed. Topics rarely reviewed include: periodic versus canonical Bloch Hamiltonian (basis I/II issue), Zak versus Berry phase, the vanishing electric polarization of the SSH model and Dirac insulators.
Understanding disorder in oxide-based electrode materials for rechargeable batteries
Authors: Christensen Christian Kolle , Ravnsbæk Dorthe Bomholdt
Published: March 2021

Most rechargeable ion batteries employ transition metal oxides or phosphates as the positive electrode. To facilitate facile migration of the active ions (e.g. Li- or Na-ions), which to some extent governs the battery functionality, the electrodes are typically composed of crystalline materials, wherein the ions are intercalated via well-defined migration pathways. However, the electrode materials are rarely perfectly crystalline and will inherently contain some disorder, which may originate from the material preparation process or be induced by the ion-intercalation process. In some electrode materials the electrochemical performance is damaged by disorder, whereas in other cases good performance is retained even after severe order–disorder transitions. This agrees with the emergence of several ab origine disordered or amorphous oxide-based electrodes with promising electrochemical performance. The term disorder is spanning a wide variety of deviations from an ideal crystal periodicity, from classical defects such as point defects, vacancies, stacking faults etc., to the amorphous state. Disorder, beyond classical defects, in battery electrodes has previously been largely overlooked, and we know little about the nature of the disorder and how it affects the battery performance. Developments in methods for characterisation of local atomic structures now allow us to gain detailed structural knowledge on the disordered part of the electrodes and studies within this field are emerging. This perspective provides a summary of the state-of-the-art within this field and the tendencies we are beginning to see outlined. These will be illustrated through selected examples. Finally, we discuss the key research questions within the field of disorder in electrode materials and the perspectives of answering these.
Data-driven discovery of Koopman eigenfunctions for control
Authors: Kaiser Eurika , Kutz J Nathan , Brunton Steven L
Published: March 2021

Data-driven transformations that reformulate nonlinear systems in a linear framework have the potential to enable the prediction, estimation, and control of strongly nonlinear dynamics using linear systems theory. The Koopman operator has emerged as a principled linear embedding of nonlinear dynamics, and its eigenfunctions establish intrinsic coordinates along which the dynamics behave linearly. Previous studies have used finite-dimensional approximations of the Koopman operator for model-predictive control approaches. In this work, we illustrate a fundamental closure issue of this approach and argue that it is beneficial to first validate eigenfunctions and then construct reduced-order models in these validated eigenfunctions. These coordinates form a Koopman-invariant subspace by design and, thus, have improved predictive power. We show then how the control can be formulated directly in these intrinsic coordinates and discuss potential benefits and caveats of this perspective. The resulting control architecture is termed Koopman Reduced Order Nonlinear Identification and Control (KRONIC). It is further demonstrated that these eigenfunctions can be approximated with data-driven regression and power series expansions, based on the partial differential equation governing the infinitesimal generator of the Koopman operator. Validating discovered eigenfunctions is crucial and we show that lightly damped eigenfunctions may be faithfully extracted from EDMD or an implicit formulation. These lightly damped eigenfunctions are particularly relevant for control, as they correspond to nearly conserved quantities that are associated with persistent dynamics, such as the Hamiltonian. KRONIC is then demonstrated on a number of relevant examples, including (a) a nonlinear system with a known linear embedding, (b) a variety of Hamiltonian systems, and (c) a high-dimensional double-gyre model for ocean mixing.
Playing optical tweezers with deep reinforcement learning: in virtual, physical and augmented environments
Authors: Praeger Matthew , Xie Yunhui , Grant-Jacob James A , Eason Robert W , Mills Ben
Published: March 2021

Reinforcement learning was carried out in a simulated environment to learn continuous velocity control over multiple motor axes. This was then applied to a real-world optical tweezers experiment with the objective of moving a laser-trapped microsphere to a target location whilst avoiding collisions with other free-moving microspheres. The concept of training a neural network in a virtual environment has significant potential in the application of machine learning for experimental optimization and control, as the neural network can discover optimal methods for problem solving without the risk of damage to equipment, and at a speed not limited by movement in the physical environment. As the neural network treats both virtual and physical environments equivalently, we show that the network can also be applied to an augmented environment, where a virtual environment is combined with the physical environment. This technique may have the potential to unlock capabilities associated with mixed and augmented reality, such as enforcing safety limits for machine motion or as a method of inputting observations from additional sensors.
Bias Analysis Gone Bad
Authors: Lash Timothy L , Ahern Thomas P , Collin Lindsay J , Fox Matthew P , MacLehose Richard F
Published: March 2021

Quantitative bias analysis comprises the tools used to estimate the direction, magnitude, and uncertainty from systematic errors affecting epidemiologic research. Despite the availability of methods and tools, and guidance for good practices, few reports of epidemiologic research incorporate quantitative estimates of bias impacts. The lack of familiarity with bias analysis allows for the possibility of misuse, which is likely most often unintentional but could occasionally include intentional efforts to mislead. We identified 3 examples of suboptimal bias analysis, one for each common bias. For each, we describe the original research and its bias analysis, compare the bias analysis with good practices, and describe how the bias analysis and research findings might have been improved. We assert no motive to the suboptimal bias analysis by the original authors. Common shortcomings in the examples were lack of a clear bias model, computed example, and computing code; poor selection of the values assigned to the bias model’s parameters; and little effort to understand the range of uncertainty associated with the bias. Until bias analysis becomes more common, community expectations for the presentation, explanation, and interpretation of bias analyses will remain unstable. Attention to good practices should improve quality, avoid errors, and discourage manipulation.
Sport Contact Level Affects Post-Concussion Neurocognitive Performance in Young Athletes
Authors: Li Adam Y , Schupper Alexander J , Quinones Addison , Shuman William H , Ali Muhammad , Hannah Theodore C , Durbin John R , Dreher Nickolas , Spiera Zachary , Marayati Naoum Fares , Gometz Alex , Lovell Mark R , Choudhri Tanvir F
Published: March 2021

Objective

Contact level affects the incidence of sports-related concussion. However, the effects of contact level on injury severity and recovery are less clear and are the focus of this study.

Method

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) for athletes aged 12–22 was performed at baseline (n = 10,907 for 7,058 athletes), after suspected concussion determined by physicians or athletic trainers (n = 5,062 for 4,419 athletes), and during follow-up visits (n = 3,264 for 2,098 athletes). Athletes played contact/collision (CC), limited contact (LC), and noncontact (NC) sports. Injury incidence, severity, and recovery were measured using raw and change from baseline neurocognitive test scores. Comparisons between groups used univariate analysis and multivariable regression controlling for demographic variables.

Results

Compared to CC athletes, LC and NC athletes showed decreased suspected concussion incidence. At initial post-injury testing, all neurocognitive test scores were similar between groups except changes from baseline for processing speed were improved for LC compared to CC athletes. Upon follow-up testing, raw neurocognitive scores were better for NC compared to the contact collision athletes in verbal memory, processing speed, total symptom score, migraine cluster, cognitive cluster, and neuropsychiatric cluster scores. For change from baseline scores, LC athletes exhibited better performance on verbal memory, processing speed, and reaction time but also showed higher neuropsychiatric scores than CC athletes.

Conclusion

Neurocognitive scores between contact levels were similar at the first post-injury test. However, follow up showed many improved scores and symptoms for limited and NC sports compared to CC sports, which may indicate faster recovery.
Characterization of a GlgC homolog from extremely halophilic archaeon Haloarcula japonica
Authors: Sueda Rin , Yoshida Kento , Onodera Masahiko , Fukui Toshiaki , Yatsunami Rie , Nakamura Satoshi
Published: March 2021

Glycogen synthesis in bacteria is mainly organized by the products of glgB, glgC, and glgA genes comprising the widely known glg operon. On the genome of extremely halophilic archaeon Haloarcula japonica, there was a gene cluster analogous to the bacterial glg operon. In this study, we focused on a GlgC homolog of Ha. japonica, and its recombinant enzyme was prepared and characterized. The enzyme showed highest activity toward GTP and glucose-1-phosphate as substrates in the presence of 2.6 m KCl and predicted to be work as “GDP-glucose pyrophosphorylase” in Ha. japonica.
Probabilistic thermodynamic analysis of metabolic networks
Authors: Gollub Mattia G , Kaltenbach Hans-Michael , Stelling Jörg
Published: March 2021

Motivation

Random sampling of metabolic fluxes can provide a comprehensive description of the capabilities of a metabolic network. However, current sampling approaches do not model thermodynamics explicitly, leading to inaccurate predictions of an organism’s potential or actual metabolic operations.

Results

We present a probabilistic framework combining thermodynamic quantities with steady-state flux constraints to analyze the properties of a metabolic network. It includes methods for probabilistic metabolic optimization and for joint sampling of thermodynamic and flux spaces. Applied to a model of Escherichia coli, we use the methods to reveal known and novel mechanisms of substrate channeling, and to accurately predict reaction directions and metabolite concentrations. Interestingly, predicted flux distributions are multimodal, leading to discrete hypotheses on E.coli’s metabolic capabilities.

Availability and implementation

Python and MATLAB packages available at https://gitlab.com/csb.ethz/pta.

Supplementary information

Supplementary data are available at Bioinformatics online.
Frequency-Dependent Cortical Interactions during Semantic Processing: An Electrocorticogram Cross-spectrum Analysis Using a Semantic Space Model
Authors: Sato Naoyuki , Matsumoto Riki , Shimotake Akihiro , Matsuhashi Masao , Otani Mayumi , Kikuchi Takayuki , Kunieda Takeharu , Mizuhara Hiroaki , Miyamoto Susumu , Takahashi Ryosuke , Ikeda Akio
Published: March 2021

Convergent evidence has demonstrated that semantics are represented by the interaction between a multimodal semantic hub at the anterior temporal lobe (ATL) and other modality-specific association cortical areas. Electrocorticogram (ECoG) recording with high spatiotemporal resolutions is efficient in evaluating such cortical interactions; however, this has not been a focus of preceding studies. The present study evaluated cortical interactions during picture naming using a novel ECoG cross-spectrum analysis, which was formulated from a computational simulation of neuronal networks and combined with a vector space model of semantics. The results clarified three types of frequency-dependent cortical networks: 1) an earlier-period (0.2–0.8 s from stimulus onset) high-gamma-band (90–150 Hz) network with a hub at the posterior fusiform gyrus, 2) a later-period (0.4–1.0 s) beta-band (15–40 Hz) network with multiple hubs at the ventral ATL and posterior middle temporal gyrus, and 3) a pre-articulation theta-band (4–7 Hz) network distributed over widely located cortical regions. These results suggest that frequency-dependent cortical interactions can characterize the underlying processes of semantic cognition, and the beta-band network with a hub at the ventral ATL is especially associated with the formation of semantic representation.
Variegated capitalism, territoriality and the renewable energy transition: the case of the offshore wind industry in the Northeastern USA
Authors: Westgard-Cruice William , Aoyama Yuko
Published: March 2021

Uneven development and the territoriality of renewable energy resources complicate prevailing theories of regional energy transitions. This article proposes a framework for the study of regional energy transitions informed by theories of variegated capitalism and geographical scholarship on the materiality and territoriality of energy. We make the case for this framework by demonstrating that the development of offshore wind energy in the Northeastern USA has been hindered by the (in)action of the US federal government, which can be explained in part by the economic importance of natural gas extraction in the underdeveloped, yet politically influential region of Northern Appalachia.
Cardiomyopathy in the peripartum period due to left ventricular non-compaction and association with Ebstein’s anomaly: a case report
Authors: Evans Emily , McDonald Mandy , Adamson Dawn L , Khan Jamal Nasir
Published: March 2021

Background

Left ventricular non-compaction (LVNC) cardiomyopathy is a persistence of abnormal foetal myocardium and is a rare cause of cardiomyopathy in the peripartum period. Unlike other causes of peripartum cardiomyopathy which typically improve, LVNC has significant long-term personal and family implications and needs lifelong follow-up.

Case summary

We describe a unique case of a 30-year-old woman who developed cardiomyopathy in the peripartum period which was revealed on cardiovascular magnetic resonance imaging to be due to occult LVNC. Our patient also had Ebstein’s anomaly, which is a known LVNC association.

Discussion

Cardiomyopathy in the peripartum period can be a decompensation of previously asymptomatic subclinical cardiomyopathy. It is important to assess for LVNC in patients presenting with this. Cardiovascular magnetic resonance imaging is the gold-standard imaging modality and allows accurate diagnosis of LVNC, associated structural complications and rare associations such as Ebstein’s anomaly. Left ventricular non-compaction is irreversible and has implications for patients and their family members.