bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental safety assessment in the influence zone of the existing Zelenchukskaya HPP-PSHS and Krasnogorsk HPP-1, HPP-2 under construction in the area of Ust-Dzhegutinsky reservoir location
Authors: Bondarenko Vladimir , Ylyasov Alla-Brerdi , Mirzoev M. , Shtavdaker Maria
Published: July 2021

«Environmental safety “in the considered spatial limits of the Upper Kuban basin geosystem (F w=11,0*103km3, W l=3,3*103km3, Watm=110*103Wb.g.U.K..=124,3*103km3) makes up about 21.4% of the spatial limits of the Kuban River, where water resources are formed according to the average long-term data about 3,0 km3, which are used in various sectors of economic activity, including for the electricity generation at Zelenchukskaya HPP-PSHS and Krasnogorsk HPP-1 and HPP-2 under construction with installed power up to 25 mW, located below the HPP-PSHS Zelenchukskaya section and above the alignment (12 km) of the Ust-Dzhegutinsky reservoir. Such HPP-PSHS placement on a 15 km long section of the Kuban Zelenchukskaya riverbed and Krasnogorsk HPP-1 and HPP-2 under construction determined a highly active zone of influence (IV), which is caused by a change in the natural hydrograph of the Kuban River, with the formation of the channel flow movement unsteady hydraulic regime in the considered section of the river to the Ust-Dzhegutinsky reservoir. Unsteady changes in the water level in the Ust-Dzhegutinsky reservoir affects the pressure front structures safety, the functional operation of the water intake system in the Bolshoi Stavropol Canal (BSC) and hydraulic BSC operation. To assess the level of “environmental safety”, it became necessary to develop a mathematical model of the impact of the HPP-PSHS functional work and Krasnogorsk HPP-1 and HPP-2 under construction at the level modes of operation of the Ust-Dzhegutinsky reservoir.
Engineering solution, increasing the environmental safety of water industry enterprises
Authors: Yuriev Yuri , Katerinin Konstantin , Konovalov Oleg , Shchitov Dmitry , Sidyakin Pavel
Published: July 2021

Drainage systems are one of the most important types of engineering equipment providing the necessary sanitary and hygienic conditions for the population life and the safe operation of industrial enterprises. A necessary condition for the long-term and reliable operation of water intake facilities (hereinafter WIF) is their effective protection against corrosion caused by various factors. Search for new engineering solutions to solve the problem of corrosion and biofouling on WIF is relevant at the moment, as it gives an opportunity to provide effective protection of WIF metal surfaces, which is directly related to the increase in the environmental performance of water enterprises.
High-altitude dynamics of snow load values on the Mount Elbrus slopes
Authors: Adzhiev Аnatoly , Bekkiev Mukhtar , Kondratieva Natalia , Yurchenko Natalia , Kubadieva Leila
Published: July 2021

The study results of the snow load values’ high-altitude dynamics, the snow cover weight value and its change with height for the designed objects of all-season tourist and recreational complex “Elbrus” at the altitudes from 2000 m to 3840.6 m are presented. Monthly measurements of the snow cover height have been carried out at various heights for this purpose. Based on the results of the snow cover height and density obtained values, a linear regression model of water content dependence in the snow cover on the height above sea level has been built. The main calculation method for finding the linear equation coefficients is the least squares technique. The calculated values of the snow cover weight on 1 m2 earth surface of different coverage have been obtained. Its value at an altitude of 3500 m above sea level is 10,42 kPa at 2% coverage and 11.16 kPa at 1% coverage.
On the assessment of the dust-air masses distribution regularity in the workshops of the reinforced concrete products’ manufacturing
Authors: Evtushenko Aleksandr , Startseva Yulia , Khoperskov Aleksandr , Azarov Valeriy
Published: July 2021

Workshops for the reinforced concrete products manufacturing belong to the type of structures, which in some cases can be called stacked [1, 2,]. Technological platforms with equipment and workplaces located on them are located at different elevations and have openings between themselves.
Intermodal transportation as a quality improvement tool in tourism industry
Authors: Devadze Anzor , Chaganava Paata , Kordzaia Irakli , Devadze Lela
Published: July 2021

The international tourism, with its developed transport infrastructure, transforms the earlier closed community into the open one, where the communications between the representatives of different countries become the everyday routine. Georgia has strategic geopolitical location on the conjunction of Europe and Asia and holds all the abilities to develop different types of passenger transportation and it enhances the further development of international tourism in the country. The authors examine the condition of country’s transport infrastructure and organization of passenger transportation via different types of transport, aiming to carry out the directions of improving the quality of tourist’s transport service and raising the competitiveness of tourism industry in Georgia, the authors proposed Intermodal Transportation Service Center as a tool of improving the quality of tourism services.
Anti-corruption audit as an imperative of effective environmental management
Authors: Nazarova Karina , Nezhyva Mariia , Hordopolov Volodymyr , Mysiuk Viktoriia
Published: July 2021

In order for the global society to emerge from the socio-economic COVID crisis, as well as to reduce its high level of eco-anxiety of various etymologies, it is necessary to restore public confidence in effective management of key segments of the national economy as an imperative of national security. In the Transparency International-19 Corruption Perceptions Index, Ukraine ranked 129th out of 180 countries (with an index of 30). The way out of the permanent state of eco-anxiety is possible only if the public information space is filled with well-founded messages about overcoming corruption risks, which are aimed at effective anti-corruption audit, which should be based on the results of basic research. The development of the region is not possible without ensuring the stable functioning of all its components: the population of the region, the state of entrepreneurship. In this case, each of the parts of the system is in correlation with each other. That is why the first direction of regional policy should be to support the introduction of eco-management in enterprises, as well as the formation of environmental behavior in the population of the region. Anti-corruption audit is an imperative for effective environmental management.
Peculiarities of financing investment infrastructure projects in Ukraine
Authors: Savina Nataliia , Kovshun Nataliia , Zhemba Alla , Ventsuryk Alisa , Klіukha Oksana
Published: July 2021

The purpose of the article is to show the role of international financial organizations in financing the development of the transportation network of Ukraine. It is shown the necessity of implementation of infrastructure projects for the development of the state economy and increase of its competitiveness. The structure of sources of financing in the development of highways is shown and the gradual reduction of the share of investments at the expense of the State budget and the insignificant role of public and private partnership in the transport sphere are revealed. The cooperation of Ukraine with international financial organizations: the International Bank of Reconstruction and Development, the European Bank of Reconstruction and Development, and the European Investment Bank in the implementation of infrastructure projects have been studied. A retrospective analysis of the available loan agreements was performed. The expected positive consequences of international investment for the transport sector of Ukraine and the economy as a whole have been identified. Information is given on real investment infrastructure projects with the participation of international financial institutions and the financial conditions of their implementation. The shifts in the arrangement of highways of Ukraine at the expense of international investments are listed.
Erratum to: New cosmic ray observations at Syowa Station in the Antarctic for space weather study
Authors: Kato Chihiro , Kihara Wataru , Ko Yukino , Kadokura Akira , Kataoka Ryuho , Evenson Paul , Uchida Satoru , Kaimi So , Nakamura Yoshiaki , Uchida Herbert Akihito , Murase Kiyoka , Munakata Kazuoki
Published: July 2021

Due to confusion in the proof correction process, the author’s proof corrections were not correctly taken into account. The corrections are listed below, highlighted by a boldface font.
Rektumkarzinom
Authors: Schmale Ine
Published: July 2021

Die Empfehlungen zur Behandlung des Rektumkarzinoms beruhen auf klinischen Studien, in denen ältere Patienten in der Regel unterpräsentiert sind. Dabei sind mehr als 40 % der Patienten bereits älter als 75 Jahre. Eine Kurzzeitradiotherapie mit verzögerter Operation scheint laut Erkenntnissen vom ASCO GI eine gute Alternative für ältere Rektumkarzinom-Patienten zu sein.
BRAF V600E-mutierte Gliome
Authors: Kretzschmar Alexander
Published: July 2021

Neue Daten, die auf der Jahrestagung der American Association for Cancer Research 2021 (AACR) präsentiert wurden, bestätigen die Kombination von Dabrafenib (Tafinlar®) und Trametinib (Mekinist®) als mögliche Therapieoption bei Patienten mit hoch- und niedriggradigen Hirntumoren mit einer BRAF V600E-Mutation.
Fortgeschrittenes Endometriumkarzinom
Authors: Christine Willen
Published: July 2021

Das fortgeschrittene Endometriumkarzinom ist mit einer hohen Sterblichkeitsrate assoziiert und bietet aktuell nur stark begrenzte Therapiemöglichkeiten. Vor diesem Hintergrund stellte Studienautorin und Onkologin Dr. Vicky Makker, New York, aktuelle Phase-III-Studiendaten aus der KEYNOTE-775/Studie 309 zu einer neuen immuntherapiehaltigen Kombination auf der virtuellen SGO-Jahrestagung.
Evidence-Based Case Report of Hydatid Cyst
Authors: Suri Purnima , Chandra Kundan Kant
Published: July 2021

Hydatid disease is a parasitic infestation in humans caused by Echinococcus granulosus. Here, it develops in liver, lung, brain or other organs but liver is the most commonly affected organ. Intensity of morbidity depends upon location, expansion and activity of cyst. In modern medicine, surgery is still the treatment of choice but the chance of relapse and other complications is always there. Homoeopathy provides a better response in such conditions. One such case report is presented below. A young female patient attended outdoor patient department chiefly for complaints of jaundice, vomiting and right hypochondriac pain for the last 1 month and her diagnosis was hydatid cyst in right lobe of liver sized 11 × 15mm (by ultrasonography). She was successfully treated with the single and individualised homoeopathic medicine Crotalus horridus in 50 millesimal potencies in respect of both symptomatically and pathologically as evident by ultrasonography reports. Possible causal attribution of changes was explicitly depicted by Modified Naranjo Criteria. It shows positive role of homoeopathic treatment in regression of hydatid cyst in a young female.
Is Homeopathy More Effective Now Than a Hundred Years Ago?
Authors: Rutten Lex , Manchanda Raj Kumar , Eizayaga José
Published: July 2021

During the past century, the amount of information about homeopathic medicines has grown dramatically. However, the recent coronavirus disease 2019 pandemic has shown that homeopathic practitioners do not use more medicines than a century ago and they seem to use less symptoms to find the proper medicine. This could be explained by the fact that the more than a hundred years old repertory was flawed from the beginning and that more information in the repertory leads the practitioner astray in an increasingly complex labyrinth of data.

This can be resolved by applying modern data management techniques based on systematic collection of treatment data and statistical analysis of the data. Homeopathic practitioners should collect these data avoiding bias. This requires additional training of practitioners, which should also result in a higher scientific level of homeopathic practice and increasingly effective treatment as the database grows.
Guiding propagation to localized target nodes in complex networks
Authors: Zhang Aobo , Zeng An , Fan Ying , Di Zengru
Published: July 2021

Spreading is an important type of dynamics in complex networks that can be used to model numerous real processes such as epidemic contagion and information propagation. In the literature, there are many methods in vital node identification and node immunization proposed for controlling the spreading processes. As a novel research problem, target spreading aims to minimize or maximize propagation toward a group of target nodes. In this paper, we consider a situation where the initial spreader emerges randomly in the network and one has to guide the propagation toward localized targets in the network. To this end, we propose a guided propagation and a reversed guided propagation model, which adaptively guides the spreading process by allocating the limited number of recovery nodes in each spreading step. We study in detail the impact of infection rate and recovery rate on the model. Simulation results show the validity of our models in most cases. Finally, we find that this adaptive target spreading can be achieved under situations with multiple groups of target nodes.
Stochastic modification of Newtonian dynamics and induced potential—Application to spiral galaxies and the dark potential
Authors: Cresson Jacky , Nottale Laurent , Lehner Thierry
Published: July 2021

Using the formalism of stochastic embedding developed by Cresson and Darses [J. Math. Phys. 48, 072703 (2007)], we study how the dynamics of the classical Newton equation for a force deriving from a potential is deformed under the assumption that this equation can admit stochastic processes as solutions. We focus on two definitions of a stochastic Newton equation called differential and variational. We first prove a stochastic virial theorem that is a natural generalization of the classical case. The stochasticity modifies the virial relation by adding a potential term called the induced potential, which corresponds in quantum mechanics to the Bohm potential. Moreover, the differential stochastic Newton equation naturally provides an action functional that satisfies a stochastic Hamilton–Jacobi equation. The real part of this equation corresponds to the classical Hamilton–Jacobi equation with an extra potential term corresponding to the induced potential already observed in the stochastic virial theorem. The induced potential has an explicit form depending on the density of the stochastic process solutions of the stochastic Newton equation. It is proved that this density satisfies a nonlinear Schrödinger equation. Applying this formalism for the Kepler potential, one proves that the induced potential coincides with the ad hoc “dark potential” used to recover a flat rotation curve of spiral galaxies. We then discuss the application of the previous formalism in the context of spiral galaxies following the proposal and computations given by Da Rocha and Nottale [Chaos, Solitons Fractals, 16(4), 565–595 (2003)] where the emergence of the “dark potential” is seen as a consequence of the fractality of space in the context of the scale relativity theory.
Superintegrable systems in non-Euclidean plane: Hidden symmetries leading to linearity
Authors: Gubbiotti G. , Nucci M. C.
Published: July 2021

Nineteen classical superintegrable systems in two-dimensional non-Euclidean spaces are shown to possess hidden symmetries leading to their linearization. They are the two Perlick systems [Ballesteros et al., Classical Quantum Gravity 25, 165005 (2008)], the Taub–NUT system [Ballesteros et al., SIGMA 7, 048 (2011)], and all the 17 superintegrable systems for the four types of Darboux spaces as determined by Kalnins et al. [J. Math. Phys. 44, 5811–5848 (2003)].
Mechanism analysis of irradiation location dependent leakage current for zinc oxide thin-film transistors
Authors: Qin Ting , Qu Zewen , Deng Lianwen , Huang Shengxiang , Liao Congwei , Luo Heng , Li Chen , Peng Yuhui , Tang Min , Gao Xiaohui
Published: July 2021

For large-area electronic applications, the mechanism of the leakage current in oxide-semiconductor thin-film transistors (TFTs) has become a critical issue. In this work, the impact of the irradiation location on the photo-leakage current of zinc oxide (ZnO) TFTs is investigated. The photo-leakage current of the ZnO TFTs is not only dependent on the light irradiation but it is also dependent on the parasitic capacitance between the drain electrode and the floating gate metal. The photo-leakage current of the source-half irradiation TFT is larger than that of the drain-half irradiation TFT. To explain this phenomenon, the profile of the electric potential and the electron concentration is analyzed by two-dimensional device simulation. It is found that the floating gate metal plays the dominant role in the photo-leakage current. This research provides insight into TFT structure optimization and high-performance TFT process development.
Inorganic cancer phototheranostics in second biowindow
Authors: Younis Muhammad Rizwan , He Gang , Gurram Bhaskar , Lin Jing , Huang Peng
Published: July 2021

Cancer phototheranostics in second biological window (1000–1500 nm) has recently emerged as a promising alternative of first biological window because of high light penetration depth, minimal tissue absorption, reduced scattering, better resolution, less autofluorescence, and high signal to noise ratio. With the rapid progress in chemical biology, nanomedicine, and material science, multifunctional inorganic phototheranostics with broadband absorption (1000–1350 nm) in near-infrared-II (NIR-II) biowindow has been actively developed to diagnose and treat deeply localized tumors simultaneously. Hence, this Perspective focuses on the latest developments in NIR-II inorganic cancer phototheranostics. A systematic comparison of NIR-I vs NIR-II biowindow has been made, followed by the technical guidelines regarding the design considerations of theranostics. The general fabrication strategies of NIR-II activated theranostics are also briefly introduced. A comprehensive discussion about the potential multimodal cancer theranostic applications of inorganic nanosystems in NIR-II biowindow has been provided, whereas the potential obstacles in clinical translation and future prospects are also highlighted in Sec. V. This Perspective will reveal the essence of NIR-II photo-induced cancer theranostics, which may push forward the development of next-generation personalized cancer photo-nanomedicines.
Enhancement of spin-to-charge conversion efficiency in topological insulators by interface engineering
Authors: He Haoran , Tai Lixuan , Wu Di , Wu Hao , Razavi Armin , Wong Kin , Liu Yuxiang , Wang Kang L.
Published: July 2021

Topological insulator (TI) based heterostructure is a prospective candidate for ultrahigh spin-to-charge conversion efficiency due to its unique surface states. We investigate the spin-to-charge conversion in (Bi,Sb)2Te3 (BST)/CoFeB, BST/Ru/CoFeB, and BST/Ti/CoFeB by spin pumping measurement. We find that the inverse Edelstein effect length (λIEE) increases by 60% with a Ru insertion while remains constant with a Ti insertion. This can be potentially explained by the protection of BST surface states due to the high electronegativity of Ru. Such enhancement is independent of the insertion layer thickness once the thickness of Ru is larger than 0.5 nm, and this result suggests that λIEE is very sensitive to the TI interface. In addition, an effectively perpendicular magnetic anisotropy field and additional magnetic damping are observed in the BST/CoFeB sample, which comes from the interfacial spin–orbit coupling between the BST and the CoFeB. Our work provides a method to enhance λIEE and is useful for the understanding of charge-to-spin conversion in TI-based systems.
Vortex wakes of tip loaded rotors at low Reynolds numbers
Authors: Bilgi O. R. , Savaş Ö.
Published: July 2021

The effect of tip tabs on the flow field of a three bladed rotor/propeller is investigated experimentally. The experiments are run at chord Reynolds numbers of Rec=0.4–2.9×105. The tab angles of attack of 0°, ∓3°, and ∓5° with respect to the rotation of the rotor are used to vary the tab loading. The rotor wakes and thrust characteristics at positive angles of attack, when the tip loading is outward, are qualitatively similar to those with no-tabs. In contrast, when the tip loading is inward at zero and negative angles of attack, the vortex wake is radically altered; the thrust nearly vanishes, even reverses with increasing inward loading. The key factors influencing the behavior of the wake are the vortex systems of the tabs and their associated downwash. The downwash is inward for the outward tab loading and causes increased volume and momentum flux in the rotor wake, and it is outward for the inward tab loading and causes expansion of the wake and nearly complete loss of thrust. When the tab loading is inward, a quasi-steady bound ring vortex system forms around at the rim of the rotor disk. At tab angle of −5°, the flow direction on the pressure side of the rotor disk reverses.
Fluid mechanics of facial masks as personal protection equipment (PPE) of COVID-19 virus
Authors: Habib A. , Habib L. , Habib K.
Published: July 2021

A fluid mechanics model of inhaled air gases, nitrogen (N2) and oxygen (O2) gases, and exhaled gas components (CO2 and water vapor particles) through a facial mask (membrane) to shield the COVID-19 virus is established. The model was developed based on several gas flux contributions that normally take place through membranes. Semiempirical solutions of the mathematical model were predicted for the N95 facial mask accounting on several parameters, such as a range of porosity size (i.e., 1–30 nm), void fraction (i.e., 10−3%–0.3%), and thickness of the membrane (i.e., 10–40 µm) in comparison to the size of the COVID-19 virus. A unitless number (Nr) was introduced for the first time to describe semiempirical solutions of O2, N2, and CO2 gases through the porous membrane. An optimum Nr of expressing the flow of the inhaled air gases, O2 and N2, through the porous membrane was determined (NO2 = NN2 = −4.4) when an N95 facial mask of specifications of a = 20 nm, l = 30 µm, and ε = 30% was used as a personal protection equipment (PPE). The concept of the optimum number Nr can be standardized not only for testing commercially available facial masks as PPEs but also for designing new masks for protecting humans from the COVID-19 virus.
Complementary switching in single Nb3O7(OH) nanowires
Authors: Ebenhoch Carola , Gänsler Thomas , Schupp Stefan , Hagner Matthias , Frank Anna , Scheu Christina , Schmidt-Mende Lukas
Published: July 2021

Single nanowires and networks are considered as promising candidates for miniaturized memristive devices for brain-inspired systems. Moreover, single crystalline nanostructures are useful model systems to gain a deeper understanding in the involved switching mechanism of the investigated material. Here, we report on hydrothermally grown single crystalline Nb3O7(OH) nanowires showing a complementary resistive switching (CRS) behavior. The CRS characteristics can be related to an oxygen vacancy migration at the electrode/metal hydroxide interface. Therefore, an oxygen plasma treatment is used to reduce the oxygen vacancy content, resulting in a total reduction of the device conductivity. Furthermore, temporal resolved current–voltage measurements demonstrate the dependence of the destructive readout process of the resistance states on the voltage amplitude and polarity.
Energetics of boron near tungsten surfaces: A first-principles study
Authors: Yang L. , Wirth B. D.
Published: July 2021

Interest exists in utilizing boron (B) wall conditioning of fusion tokamaks containing tungsten (W) plasma facing components, in order to improve plasma confinement. To understand the interactions of B with W surfaces, first-principles density functional theory calculations have been performed to model the adsorption, diffusion, and solution of B near the W(100), W(110), and W(111) surfaces. The results show that B within a distance of 0.6 nm above the surfaces is adsorbed to the surfaces without activation barriers. B atoms are strongly adsorbed on the W(100) surface with an adsorption energy of 7.80 eV, which is 1.22 and 1.35 eV larger than on the W(110) and W(111) surfaces. B diffusion on the W(100), W(110), and W(111) surfaces has an activation energies of 2.08, 1.12, and 1.47 eV, respectively; while, diffusion from the adsorption sites into the bulk requires 2.2–2.3 eV. The B solution energy below a clean W(100) surface is the lowest, followed by the W(111) and W(110) surfaces. B clustering and B-induced surface deformation as a function of B coverage has been investigated. B on the W(100) surface occupy epitaxial sites at coverages of 0–1.25 ML, but form clusters at higher coverages. B clustering on the W(110) and W(111) surfaces is expected throughout the adsorption process. Compared to a clean surface, B atoms on the W(100) reduce the surface effect on the B solution energy below the surface, while the presence of B on the W(110) and W(111) surfaces generally decreases or increases the B solution energy below surfaces, respectively.
On the feasibility of wireless radio frequency ablation using nanowire antennas
Authors: Rommelfanger Nicholas J. , Hong Guosong
Published: July 2021

Radio frequency ablation (RFA) is a proven technique for eliminating cancerous or dysfunctional tissues in the body. However, the delivery of RFA electrodes to deep tissues causes damage to overlying healthy tissues, while a minimally invasive RFA technique would limit damage to targeted tissues alone. In this manuscript, we propose a wireless RFA technique relying on the absorption of radio frequencies (RFs) by gold nanowires in vivo and the deep penetration of RF into biological tissues. Upon optimizing the dimensions of the gold nanowires and the frequency of the applied RF for breast cancer and myocardium tissues, we find that heating rates in excess of 2000 K/s can be achieved with high spatial resolution in vivo, enabling short heating durations for ablation and minimizing heat diffusion to surrounding tissues. The results suggest that gold nanowires can act as “radiothermal” agents to concentrate heating within targeted tissues, negating the need to implant bulky electrodes for tissue ablation.
Relationship between mutual information and cross-correlation time scale of observability as measures of connectivity strength
Authors: Perinelli Alessio , Castelluzzo Michele , Tabarelli Davide , Mazza Veronica , Ricci Leonardo
Published: July 2021

The task of identifying and characterizing network structures out of experimentally observed time series is tackled by implementing different solutions, ranging from entropy-based techniques to the evaluation of the significance of observed correlation estimators. Among the metrics that belong to the first class, mutual information is of major importance due to the relative simplicity of implementation and its relying on the crucial concept of entropy. With regard to the second class, a method that allows us to assess the connectivity strength of a link in terms of a time scale of its observability via the significance estimate of measured cross correlation was recently shown to provide a reliable tool to study network structures. In this paper, we investigate the relationship between this last metric and mutual information by simultaneously assessing both metrics on large sets of data extracted from three experimental contexts, human brain magnetoencephalography, human brain electroencephalography, and surface wind measurements carried out on a small regional scale, as well as on simulated coupled, auto-regressive processes. We show that the relationship is well described by a power law and provide a theoretical explanation based on a simple noise and signal model. Besides further upholding the reliability of cross-correlation time scale of observability, the results show that the combined use of this metric and mutual information can be used as a valuable tool to identify and characterize connectivity links in a wide range of experimental contexts.
Observations regarding deep-level states causing p-type doping in AlTiO gate and positive threshold voltage shift in AlGaN/GaN high electron mobility transistors
Authors: Dutta Gupta Sayak , Joshi Vipin , Roy Chaudhuri Rajarshi , Shrivastava Mayank
Published: July 2021

Application of ternary oxides has emerged as a potential enabler to achieve enhancement mode (normally-OFF) operation in AlGaN/GaN high electron mobility transistors (HEMTs). However, it is not well understood what leads to the 2-Dimensional Electron Gas depletion or positive threshold voltage shift by the integration of these oxides in the gate stack. In this work, an electro-optical experiment-based method is used to probe the underlying mechanism. For experiments, AlGaN/GaN metal–oxide–semiconductor high electron mobility transistors with gate stack consisting of AlTiO (ternary p-type oxide), Al2O3, TiO2 (undoped binary oxides), and NiO (conventional p-type oxide) are used. Optical exposure with wavelengths falling in the UV regime (365 nm) was found to induce a negative threshold voltage shift in AlTiO based devices. Experimentation on different GaN buffer stacks, different gate oxides, and selective UV exposure only to the gate region established the phenomenon to be governed by properties of the ternary oxide. This was further confirmed by the fact that the negative threshold voltage shift with UV exposure was proportional to the positive shift achieved as a function of Al% in AlTiO. The negative shift was found to be due to de-ionization of deep-level negative states in AlTiO, which resulted from the presence of Al at Ti sites ([Al]Ti′). These negatively ionized deep-level states at room temperature result in p-type doping of the oxide, leading to the positive threshold voltage shift in AlTiO gate based HEMTs when compared with HEMTs with Al2O3 or TiO2 as gate oxide.
An efficient Fock space multi-reference coupled cluster method based on natural orbitals: Theory, implementation, and benchmark
Authors: Haldar Soumi , Dutta Achintya Kumar
Published: July 2021

We present a natural orbital-based implementation of the intermediate Hamiltonian Fock space coupled-cluster method for the (1, 1) sector of Fock space. The use of natural orbitals significantly reduces the computational cost and can automatically choose an appropriate set of active orbitals. The new method retains the charge transfer separability of the original intermediate Hamiltonian Fock space coupled-cluster method and gives excellent performance for valence, Rydberg, and charge-transfer excited states. It offers significant computational advantages over the popular equation of motion coupled cluster method for excited states dominated by single excitations.
Hydration of methemoglobin studied by in silico modeling and dielectric spectroscopy
Authors: Latypova Larisa , Puzenko Alexander , Poluektov Yuri , Anashkina Anastasia , Petrushanko Irina , Bogdanova Anna , Feldman Yuri
Published: July 2021

The hemoglobin concentration of 35 g/dl of human red blood cells is close to the solubility threshold. Using microwave dielectric spectroscopy, we have assessed the amount of water associated with hydration shells of methemoglobin as a function of its concentration in the presence or absence of ions. We estimated water–hemoglobin interactions to interpret the obtained data. Within the concentration range of 5–10 g/dl of methemoglobin, ions play an important role in defining the free-to-bound water ratio competing with hemoglobin to recruit water molecules for the hydration shell. At higher concentrations, hemoglobin is a major contributor to the recruitment of water to its hydration shell. Furthermore, the amount of bound water does not change as the hemoglobin concentration is increased from 15 to 30 g/dl, remaining at the level of ∼20% of the total intracellular water pool. The theoretical evaluation of the ratio of free and bound water for the hemoglobin concentration in the absence of ions corresponds with the experimental results and shows that the methemoglobin molecule binds about 1400 water molecules. These observations suggest that within the concentration range close to the physiological one, hemoglobin molecules are so close to each other that their hydration shells interact. In this case, the orientation of the hemoglobin molecules is most likely not stochastic, but rather supports partial neutralization of positive and negative charges at the protein surface. Furthermore, deformation of the red blood cell shape results in the rearrangement of these structures.
Effect of free-stream inclination and buoyancy on flow past a square cylinder in large-scale heating regime
Authors: Arif Md. Reyaz , Hasan Nadeem
Published: July 2021

The combined effects of free-stream inclination (α) and heating [ϵ=(Tw−T∞)/T∞] on aerodynamic and heat transfer parameters are studied at fixed Reynolds number (Re = 100), Prandtl number (Pr = 0.71), cylinder inclination (ϕ=0°), Froude number (Fr = 1.0), and Mach number (M = 0.1) in the large-scale heating regime. For this purpose, a non-Oberbeck–Boussinesq compressible model for thermally perfect gases incorporating volumetric straining as well as transport property variations under large-scale heating is employed. The free-stream inclination (α) is varied in the range [0°, 90°] while the over-heat ratio (ϵ) is varied in the range of [0, 1]. It is found that at small free-stream inclinations (α≤45°), increase in heating causes a significant increase in mean drag coefficient, while at large α (α>45°), heating has little effect on mean drag coefficient. The mean lift coefficient (CL) increases by increasing ϵ for any value of α except α = 0. At a fixed heating level, the variation of mean CL is very non-monotonic with lower values at α=45° and 90°. It is found that the increase in flow inclination from 0° to 90° reduces the sensitivity of Strouhal number (St) to heating. For ϵ≤0.6, mean Nusselt number exhibits a non-monotonic trend with increase in α and attains a maximum value at α ≅ 40°. However, for ϵ>0.6, heat transfer decreases with increase in α and is maximum for aligned flow (α=0°).
Internal conversion of singlet and triplet states employing numerical DFT/MRCI derivative couplings: Implementation, tests, and application to xanthone
Authors: Bracker Mario , Marian Christel M. , Kleinschmidt Martin
Published: July 2021

We present an efficient implementation of nonadiabatic coupling matrix elements (NACMEs) for density functional theory/multireference configuration interaction (DFT/MRCI) wave functions of singlet and triplet multiplicity and an extension of the Vibes program that allows us to determine rate constants for internal conversion (IC) in addition to intersystem crossing (ISC) nonradiative transitions. Following the suggestion of Plasser et al. [J. Chem. Theory Comput. 12, 1207 (2016)], the derivative couplings are computed as finite differences of wave function overlaps. Several measures have been taken to speed up the calculation of the NACMEs. Schur’s determinant complement is employed to build up the determinant of the full matrix of spin-blocked orbital overlaps from precomputed spin factors with fixed orbital occupation. Test calculations on formaldehyde, pyrazine, and xanthone show that the mutual excitation level of the configurations at the reference and displaced geometries can be restricted to 1. In combination with a cutoff parameter of tnorm = 10−8 for the DFT/MRCI wave function expansion, this approximation leads to substantial savings of cpu time without essential loss of precision. With regard to applications, the photoexcitation decay kinetics of xanthone in apolar media and in aqueous solution is in the focus of the present work. The results of our computational study substantiate the conjecture that S1  T2 reverse ISC outcompetes the T2 ↝ T1 IC in aqueous solution, thus explaining the occurrence of delayed fluorescence in addition to prompt fluorescence.
Generative adversarial networks with physical evaluators for spray simulation of pintle injector
Authors: Ma Hao , Zhang Botao , Zhang Chi , Haidn Oskar J.
Published: July 2021

Due to the adjustable geometry, pintle injectors are especially suitable for liquid rocket engines, which require a widely throttleable range. However, applying the conventional computational fluid dynamics approaches to simulate the complex spray phenomenon in the whole range still remains a great challenge. In this paper, a novel deep learning approach used to simulate instantaneous spray fields under continuous operating conditions is explored. Based on one specific type of neural network and the idea of physics constraint, a Generative Adversarial Networks with Physics Evaluators framework is proposed. The geometry design and mass flux information are embedded as inputs. After the adversarial training between the generator and discriminator, the generated field solutions are fed into two physics evaluators. In this framework, a mass conversation evaluator is designed to improve the training robustness and convergence. A spray angle evaluator, which is composed of a down-sampling Convolutional Neural Network and theoretical model, guides the networks to generate the spray solutions more closely according to the injection conditions. The characterization of the simulated spray, including the spray morphology, droplet distribution, and spray angle, is well predicted. This work suggests great potential for prior physics knowledge employment in the simulation of instantaneous flow fields.
Experiment on bubble formation through dynamical wetting transition in a square capillary
Authors: Wu Chang-E , Du He-Wei , Qin Jian , Li Er-Qiang , Gao Peng
Published: July 2021

We experimentally study the displacement of viscous liquid by gas in a square capillary tube. The liquid is partially wetting in a way that no spontaneous imbibition along the interior corners would occur even in the absence of forced displacement. The gas–liquid interface exhibits a variety of morphologies with an increasing displacement rate. At a low displacement rate, a constantly moving meniscus can be observed, without any liquid deposition on the tube wall. An increase in the displacement rate gives rise to the deposition of two ultra-thin liquid filaments at each corner, which immediately break into tiny droplets. An additional thicker filament is entrained at each corner as the displacement rate further increases, connecting the thinner ones and the meniscus. When the displacement rate is high, liquid films are entrained on the tube wall and eventually collapse, entrapping an amount of gas in the form of Taylor bubbles. Quantitative measurements show that both the thicker filaments and the liquid films retract at constant speeds. Empirical relations predicting the film thickness and the bubble length are proposed and agree with the experimental results.
Assessing the impacts of scale residues from offshore oil and gas decommissioning on marine organisms
Authors: Cresswell Tom , Brown Sue , Wong Henri , Apte Simon
Published: July 2021

Successful decommissioning of offshore oil and gas infrastructure requires an effective and safe approach to assessing and managing chemical and radiological residues. Scale frequently accumulates on the interior surfaces of pipes and other structures and may persist long after extraction operations have ceased. Scale materials can contain a range of metal contaminants (including mercury), as well as naturally occurring radioactive materials. In newer or more accessible infrastructure, the scale is routinely removed, and becomes a waste product. The persistent nature of scale contaminants can result in a radiological dose to the organisms living on, or near an intact pipeline. Eventually, infrastructure corrosion following insitu decommissioning (abandonment) could lead to metal and radionuclide contaminants being accessible to the surrounding seafloor environment, where bioaccumulation and subsequent ecotoxicological effects from the chemical and radiological properties of the scale could occur. The paper describes a tiered approach to assess the ecological impacts of pipeline scale in order to assist operators with their plans for decommissioning offshore infrastructure, especially when considering ‘leave in place’ options.
Blockchains – achieving consensus in oil and gas business processes
Authors: Waller Scott
Published: July 2021

As the oil and gas industry comes under increasing pressure from government, activist groups and society on carbon offsetting, a trend that is building is the disclosure of consistent, comparable and reliable data. As companies develop their abatement plans, it is critical that the accounting and reporting of activities are made transparent or companies risk not achieving the social license to operate they are aiming to build. This proposal will discuss the opportunity for operators to use blockchain to digitise the information and processes that operate between unincorporated joint ventures, companies and third parties they deal with – customers, suppliers, government and society. At its heart, blockchain is a distributed ledger that offers the potential to make processes between companies more efficient through standardised processes and trusted data; in the same way companies have implemented internal Enterprise Resource Planning systems to achieve this goal within their own entities. The current landscape of systems and processes has been set up to optimise internally, but when processes cross company boundaries, they execute via email and analogue processes. Gartner predicts that by 2030 $3.1 trillion of goods and services will be tracked by blockchain technology. This is a technology that will revolutionise supply chains and company-to-company interactions. The energy sector has embraced contractors and suppliers who support engineering, operations, maintenance, services and supply of parts. Blockchain is therefore a technology that offers great opportunity in optimising in-bound supply chain and increasingly will be required to communicate on their outbound product with more transparent and trusted data enabled by blockchain technology.
Embracing Australia's decommissioning liability
Authors: Taylor Andrew , Stokes Stephen
Published: July 2021

Improving visibility of when and where oil and gas assets are approaching end of life has provided the foundation for transformation of decommissioning planning and execution around the world. A baseline understanding of decommissioning established by Oil and Gas UK fed into the much lauded Maximising Economic Recovery strategy, and provided a platform for government to pursue a 35% cost reduction target for decommissioning in the United Kingdom. In the Netherlands, one of the first four priorities pursued to maximise value through decommissioning was the establishment of a national decommissioning database, which aimed to create an integrated view of decommissioning scope and timelines. In 2020, funded by NERA and a group of seven operators, Advisian delivered the first operator-supported assessment of Australia's decommissioning liability and outlook. This outlook lays the foundation for initiatives that support knowledge sharing, service sector engagement, collaboration, technology development, efficiency and reduced stakeholder burden. This joint presentation by NERA and Advisian will provide an overview of NERA's decommissioning strategy and the data that underpins this strategy, the Advisian ‘Offshore Oil and Gas Decommissioning Liability' assessment for Australia.
A framework for inclusion of faults in coal seam gas risk assessments
Authors: Murray Titus A. , Power William L.
Published: July 2021

Assessments for coal seam gas (CSG) projects may be required to consider the potential hydrological impacts of faults on surface and near-surface groundwater assets. This study presents three distinct end-member geological scenarios and outlines methods for characterising fault-related groundwater flow within a risk assessment context.
Scenario 1: a regional aquitard isolates the water assets from the coal seams. There is little risk of leakage across the aquitard because there are no faults, or because the faults have maximum displacements less than the thickness of the aquitard.
Scenario 2: a region-wide aquitard is not present, and the seams and the groundwater assets are located within the same groundwater system. In this scenario, CSG development may cause pressure changes to propagate parallel to the strike and dip of the fault in the fault damage zones.
Scenario 3: regional aquitard(s) are present, but larger displacement faults breach the aquitards, allowing for possible combinations of across-fault connections between the different aquifers, and between aquifers and the coal seams. In this scenario, potential flow pathways between the groundwater and the CSG field need to be characterised using Allan Maps (fault plane profiles).

It is essential to compare calculated flow rates of any new or potentially new flow pathways with the predevelopment flow regime. It is also important to recognise that flow estimates are best made using a Darcy’s law treatment for flow across fault zones and within the aquifers, and a Snow’s law treatment (discrete fracture network) for flow through fractures in fault damage zones.
Controls on gravity-driven normal fault geometry and growth in stacked deltaic settings: a case study from the Ceduna Sub-basin
Authors: Jimenez Monica , Holford Simon P. , King Rosalind C. , Bunch Mark A.
Published: July 2021

Kinematics of gravity-driven normal faults exerts a critical control on petroleum systems in deltaic settings but to date has not been extensively examined. The Ceduna Sub-basin (CSB) is a passive margin basin containing the White Pointer (Albian-Cenomanian) and Hammerhead (Campanian-Maastrichtian) delta systems that detach on shale layers of Albian-Cenomanian and Turonian-Coniacian ages, respectively. Here we present evidence for spatially variable fault growth styles based on interpretation of the Ceduna 3D seismic survey and fault kinematic analyses using displacement–distance, displacement–depth and expansion index methods. We identified faults that continuously grew either between the Cenomanian–Santonian or Santonian and the Maastrichtian located throughout the study area and faults that exhibit growth between the Cenomanian–Maastrichtian that are geographically separated into three areas according to their evolution histories: (i) Northern CSB faults exhibit constant growth between the Cenomanian and Maastrichtian. (ii) Central CSB faults show two dip-linkage intervals between (a) Cenomanian and Coniacian–Late Santonian, (b) Coniacian–Late Santonian and Late Santonian–Maastrichtian segments, respectively. (iii) Central and southern CSB faults exhibit dip-linkage intervals between Cenomanian–early Santonian and Late Santonian–Maastrichtian segments. Our study demonstrates a relationship between the location of the Cenomanian–Maastrichtian faults and their evolution history suggesting constant growth evolution at north and dip linkage at the central and south areas.