bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymptotic regularisation of the solution to the problem of electromagnetic field scattering from a set of small impedance particles
Authors: Andriychuk Mykhaylo
Published: July 2021

The solution to the problem of electromagnetic (EM) wave scattering from a set of small‐size impedance particles of arbitrary shape is derived by the asymptotic approach. Particles are located in a homogeneous domain with constant ɛ0 and μ0. The solution is derived under the condition b → 0, where b is the characteristic size of the particle; further, the number M(b) of particles tends to infinity at a specific rate. The regularising procedure consists of the derivation of the explicit form of a solution that excludes the necessity to solve the respective integral equation for determination of the fields at the surface of particles and thus avoids integrating the Green function derivatives, which are in the kernel of this boundary integral equation. Practical application of this approach yields an ability to create media with the desired inhomogeneous distribution of effective refractive index n and magnetic permeability μ(x). Explicit analytical formulas are derived for these physical parameters and supported by computations.
Functional units modelling of the controller for the energy-efficient power converters hardware
Authors: Boldyrev Alexander
Published: July 2021

The functional units SPICE-models design steps of the controller K1156EU2 using Micro-Cap 12 computer assisted circuit design software. Presented methodology includes functional analysis of the units. Developed models are used as the baseline components for the controllers’ SPICE-macromodel. The models and respective key characteristics are aligned with and represent fully all claimed hardware counterparts’ specifications. Each model can be tuned through the respective set of parameters, hence enabling energy consumption characteristics optimization during the design phase.
Study increase the mechanical characteristics of tool materials by cryogenic treatment
Authors: Puchkin Vladimir , Turkin Ilya , Salanti Larisa , Sumskaja Olga , Kornienko Vladimir
Published: July 2021

In this work, the hypothesis of taking into account a specific thermoEMF to determine the degree of hardening of the cutting tool by cryogenic hardening is put forward, which is the most convenient and important value from the point of view of information content. As a result of studies of improving the mechanical characteristics of instrumental materials by cryogenic treatment, the values of the absolute and specific values of thermo emf were revealed depending on the temperature of three instrumental materials obtained by tarrying them together with platinum. The values of temperatures at the maximum values of the specific thermo emf, have been obtained. It was found that deep cooling of the metal increases the degree of ordering of its structure and increases the vibrational energy of the crystal lattice. The results of the study showed that the resistance of the cryogenic cutting tool increases by up to three times, this positively affects the energy efficiency of the use of such a tool in production. The reduction of energy costs is expressed in the reduction of kilowatt-hours associated with the costs of sharpening the tool and can reach up to 30% of the total amount of electricity consumed.
Reduce energy loss with dynamic positioning controller for USV based on Hierarchical Sliding Mode Control
Authors: Nguyen T.K. , Le Th.Tr. , Nguyen C.X.
Published: July 2021

This paper presents a positional stabilization controller for the under-actuators USV model based on a Hierarchical Sliding Mode Control System (HSMC) that takes into account environmental influences when operating as the flow, waves and wind. The controller presents successful simulation results demonstrating stability in the presence of noise. It helps to reduce energy loss in human activities at the sea.
Design control system for Pan-Tilt Camera for Visual Tracking based on ADAR method taking into account energy output
Authors: Tran Ph.C. , Nguyen H.Tr. , Nguyen A.Q. , Le Th.Tr. , Phan H.Ng. , Nguyen C.X.
Published: July 2021

In this paper, we propose a controller for a camera-based Pan-Tilt device. The approach uses the target image feature to steer the Pan-Tilt device to the target with random movement. Since these systems are often mounted on mobile equipment, energy efficiency should also be taken into account. In order to improve the control energy consumption efficiency of the Pan-Tilt system mounted with cammera, the authors use a dark objective function with optimal energy components to find controller parameters. Simulation results on the PanTilt system show that the camera can track a moving target quickly and stably and the control energy can be changed through the controller parameter according to the purpose of use.
Design of national meat and vegetable products for baby food
Authors: Vasyukova Anna , Karpov Valeriy , Makhmadaliyev Erac , Valentinova Nina , Yegorova Svetlana
Published: July 2021

The article presents studies on the optimization of recipes and nutritional value of national meat and vegetable products enriched with vegetable products: cabbage, carrots and pumpkin, for the nutrition of school children of 7-11 years old. Using the method of mathematical modeling, a reference sample, a blend was determined, and the formulation of a multicomponent protein-containing product was optimized.The method of selection of components was used to select promising ingredients for combining traditional recipes for minced meat. It was found that pumpkin, zucchini, cabbage and carrots. On theon the basis of organoleptic and physicochemical studies for the production of model minced meat were selected vegetable components in the ratio of meat: vegetable raw materials for blend No. 1 62: 34, and for blend No. 2 65: 29. The recipe was optimized by the method of integer nonlinear mathematical programmingfor the optimality criterion of blend No. 1, k = 2.04, and for blend No. 2, k = 0.81. Received, The recipe for meat and vegetable minced meat in terms of the ingredient composition will be as close as possible to the reference sample, which is 10% of the daily set of food products for the nutrition of school children of the age category 7-11 years.
Application of feed additives derived from fermented spring wheat straw in broiler poultry farming
Authors: Dedkova Antonina , Sergeyeva Natalia
Published: July 2021

Studied the growth and safety of broiler chickens after replacing 10% of the grain in the feed mixture with feed additives, which are prepared from cellulose-containing raw materials by enzymatic hydrolysis (spring soft wheat straw). It was experimentally established that feeding with feed additives had a positive effect on the safety of broiler chickens; there was no negative effect on the growth rates of chickens.
Study of the amino acid composition of thermoacid coagulation fractions of probiotic products
Authors: Rodionova Natalia , Popov Evgeny , Pozhidaeva Ekaterina , Zakharova Natalia , Syromyatnikov Michael
Published: July 2021

The developed mathematical model allows good prediction of the quantity of heat saved based on applied technological parameters. The process of distribution of amino acids between whey and protein clot was studied during thermoacid coagulation of milk fermented by a consortium of bifidobacteria Lactococcus lactis subsp. diacetilactis, Streptococcus thermophiles, Propionibacterium freudenreichii, Bifidobacterium bifidum with an active cell concentration of 109 CFU/ml. The distribution of amino acids indicates the predominant transition of amino acids of microbial origin into coagulum. An increase in the content of such amino acids as lysine and leucine was found, the concentration of valine, isoleucine, methionine, threonine, phenlalanine, which had a rate of more than 100%, decreased. The predominant transfer of microbial exopolysaccharides - metabolic products of probiotic microorganisms - is noted in serum, which makes it an especially valuable biological resource for the production of eubiotic drinks.
Modelling of the bread recipe composition to improve effectiveness of the production process
Authors: Ponomareva Elena , Lukina Svetlana , Alekhina Nadezhda , Malyutina Tatiana , Pavlovskaya Svetlana
Published: July 2021

This paper looks into the combined influence of untraditional types of raw materials on the quality of wheat flour bread and the effectiveness of the technological process. To estimate that, the methods of mathematical planning and experiment optimisation were applied. The main factors were the dosage of recipe components such as turmeric and liquid grape sugar, the output parameters were unit volume and shape stability of a product. The optimisation of the recipe composition was carried out by the method of folding partial criteria in generalised additive criteria. Rational criteriameanings were determined: the dosage of liquid grape sugar – 2,50 %, turmeric – 2,75 %, which guarantee the production of products with the best combination of values of specific volume and dimensional stability. Basing on the data obtained, there was elaborated the formula of the bread «Merita» (TU 9110-515-02068108-2019) which is characterised with improved quality and higher nutritional value. The application of this technology will allow to increase output of product by 3 % and reduce the production cycle by 1,5 hours.
Comparative analysis of linear and non-linear free vibrations of harmonic oscillator
Authors: Kulterbaev Khusen , Vodakhova Valentina , Baragunova Lyalusya , Dadova Marina , Shogenova Mariana
Published: July 2021

Free vibrations of a harmonic oscillator in the form of a mathematical pendulum in linear and nonlinear formulations are considered. Their comparative analysis is carried out as a conservative system with one degree of freedom. To solve a nonlinear differential equation, the finite difference method and Euler’s scheme are used. Specific examples are given, the limits of the mathematical pendulum deviations angles, at which the solutions of linear and nonlinear problems practically coincide, are determined. The law of potential and kinetic energy sum conservation is used for the oscillations of conservative systems. The conclusions are drawn for the practical application of the results obtained.
The nonclassical problem of the compressed bar stability
Authors: Kulterbaev Khusen
Published: July 2021

The non-classical problem of the stability loss of a straight vertical bar with elastic flexible elements at the ends is considered. The mathematical model for the study of stability loss consists of a linearized differential equation for buckling of a constant cross section bar, supplemented by boundary conditions. Critical force is determined by analytical and numerical methods. Two versions of computational algorithms are presented. For one design scheme of the rod in the Matlab computing environment, the critical forces are calculated using two methods. The found critical forces differ insignificantly, which confirms the reliability and efficiency of the proposed algorithms.
General theory and foundations for calculating reinforced concrete structures of buildings and structures in modern construction
Authors: Sanjarovskiy Rudolf , Sieber Frieder , Ter-Emmanuilyan Tatyana
Published: July 2021

The theory which consists of two parts: short-term and long-term loading and of five inconsistent (or erroneous) theories that reject the fundamental properties of structural concrete and the principles of Eurocode and which is used in the calculations of various buildings and structures is analyzed.
Stress-strain state of the short eccentrically compressed reinforced concrete columns with nonlinear creep
Authors: Chepurnenko Anton , Dubovitskaya Ludmila , Vanja Vladimir , Tenemaza Ortega Damian Israel , Kuznetsov Andrey
Published: July 2021

The article presents the derivation of the resolving equations for calculating short eccentrically compressed reinforced concrete elements taking into account the creep of concrete. The case of symmetric reinforcement is considered. A viscoelastoplastic model of hereditary aging by A.G. Tamrazyan is used. Comparison of solutions based on linear and nonlinear creep theory is performed.
Industrial construction of the late XIX-early XX centuries: barracks for workers of the Moscow region manufactories
Authors: Shamaeva Tatyana
Published: July 2021

In this paper, the objects of research are barracks for workers of industrial manufactories of the late XIX - early XX centuries, situated in the Moscow region.

Recommendations for the functional purpose of these buildings:

Residential function with apartments of 1 comfort category, improved design; colivings.

Guesthouses, hotels.

Public function: offices, exhibitions, museums, medical institutions, food facilities, trade, beauty salons, hairdressers, household services and minor repairs can be located on the first floors of the building. Leisure centers for different age groups, clubs for children and young people, fitness centers.
Investigation of the SHS process initiation in the base mixture during HFC heating and the dependence of the combustion rate on various factors
Authors: Malikov Vladimir , Ishkov Alexey
Published: July 2021

This work is devoted to the study of promising materials - liquid-phase systems aluminum-boron oxide. These materials after SHS process form a boride coating that provides high strength and wear resistance of steel parts. The article describes the features of the initiated SHS process and the nature of the mixture combustion, studies of the HFC heating effect for SHS process. At the first research stage, the dependence of initiation SHS in all investigated compositions on the characteristic size of the sample and the composition of the base mixture was determined. The combustion rate was estimated from the combustion time of the sample from one end of the sample to the other. The burning rate was also estimated SHS-compositions on the particle size of the reagents. At the second stage of the research, the composition of the base mixture was modified by the introduction of a flux P-0.66. The addition of flux made it possible to significantly reduce the burning rate and compare in time SHS process obtaining boron during combustion of a modified composition and the process of HFC boriding high-speed.
Game as a scientific and methodological basis of modern geodetic education
Authors: Dudnik Anastasia , Tupoleva Galina
Published: July 2021

Modern level of scientific and technical development in the field of geodetic and cartographic activity associated with the use of satellite geodetic methods, the widespread introduction of new technical means and technologies, requires highly qualified specialists who are able to solve complex production and scientific problems in the field of geodesy. This is the reason for the new teaching methods’ emergence. It is worth noting that the evaluative control implementation of knowledge, skills and abilities in a playful form allows the teacher to provide the necessary assistance to the student in a timely manner, to guide him, develops and activates the independent work of students, and also creates comfortable conditions for successful mental activity formation.
The relationship between the production and construction sector and continuous professional training
Authors: Pesotskaya Elena , Selyutina Larisa , Ivanova Maria , Egorova Olga
Published: July 2021

The article reveals the economic nature of the relationship between the production and construction process and continuous professional training, as well as the methods of their use in practice - in effective management decisions formation. Special emphasis is placed on the role of continuous professional training in providing the production and construction sector with specialists of the required qualification level. The possibilities of monitoring continuous professional training and its parametric range are analyzed. The universality of methodology and tools for managing continuous professional training is noted in the presence of a number of features that reflect the mechanisms of the construction industry functioning.
Integrated simulation of bio positive environment in a large city through the reconstruction of its recreational areas
Authors: Paramonova Oksana , Lysova Ekaterina , Yudina Natalya
Published: July 2021

In the presented article, the concept of “bio-positivity” is considered as a way of returning the natural habitat to largest cities. The problem of the aesthetic unattractiveness in modern cities, the causes and consequences of rational construction without taking into account the ecological component is outlined. Various solution methods for the natural environment restoration in large cities have been proposed. Environmental friendliness and focus on preserving the environment are highlighted as the main criteria.
Lower seroprevalence of Toxoplasma gondii in swine from central China after an outbreak of African swine fever
Authors: Xie Weitao , Xin Shilin , Jiang Nan , Zhang Gaiping , Zhang Longxian , Li Xiangrui , Yang Yurong
Published: July 2021

Toxoplasma gondii is widespread worldwide and can infect swine. This study evaluated the seroprevalence of T. gondii in swine from central China after an outbreak of African swine fever (ASF). A total of 2683 swine serum samples were collected from farms in four provinces. Of the serum samples, 1.42% (38/2683) (95% CI, 1.03–1.94) tested positive for T. gondii IgG antibody by a modified agglutination test (MAT) (cut-off: 1:25). Comparing with the results of previous studies, specifically our survey from before the outbreak, the seroprevalence of T. gondii in swine from central China was significantly decreased after the occurrence of ASF (OR = 7.679, 2015–2017 vs. 2019–2020). In general, the proportion of seropositive animals increased with the age of the swine, indicating post-natal transmission of T. gondii. Furthermore, there was a significant difference in seroprevalence between suckling pigs and weaned pigs (p < 0.05). This is the first large-scale investigation of T. gondii infection in swine after an ASF outbreak in China. The lower seroprevalence of T. gondii in swine after ASF may be due to stricter biosecurity measures on the farms, but results indicated swine exposure to zoonotic parasites despite these measures. This highlights that pigs must be considered a potential source of human T. gondii infections.
Auf das WIE kommt es an – Mindful Occupation
Authors: Kranz Florence
Published: July 2021

Während wir handeln, können wir in unterschiedlichem Ausmaß präsent, bewusst, engagiert oder erfüllt sein und uns mehr oder weniger wohlfühlen. All diese Aspekte spielen eine Rolle, wenn es um „Mindful Occupation“ geht. Also um die Frage, wie achtsam wir uns betätigen. Der Artikel beschäftigt sich mit dem aktuellen Wissens- und Erkenntnisstand zu diesem Konstrukt und beleuchtet ausgewählte Literatur aus der Occupational Science und Ergotherapie.
The Challenges of Treating Neovascular Age-Related Macular Degeneration
Authors: Hollaus Marlene , Bühl Wolf , Schmidt-Erfurth Ursula , Sacu Stefan
Published: July 2021

Age-related macular degeneration (AMD) is one of the main causes of visual impairment and blindness in patients over 60 years in developed countries. Whilst no effective form of therapy is
available for the dry form of AMD, intravitreal application of anti-VEGF substances is able to prevent the progression of neovascular AMD (nAMD) in most cases. Aside from the drugs
ranibizumab, aflibercept and brolucizumab, other agents such as bevacizumab are often used off-label in order to save expense. The treatment intervals have also been refined, so as to reduce
the burden on patients and health care systems. After fixed injection intervals, the pro re nata-regimen has been developed. Each month, it is decided whether the patient receives
intravitreal injections based on fixed criteria. In the treat and extend-protocol, patients receive injections on each visit, but the intervals between injections vary due to the clinical
outcomes. The observe-and-plan regime allows scheduling of the injection intervals in blocks, for three consecutive injections at a time. However, results of real-world studies were not able
to reproduce those obtained in the pivotal studies. A high number of visits and fear of the injection procedure impose a burden on patients, that is mostly accepted due to fear of vision
loss. Caregivers also complain of loss of productivity and income from having to provide regular support to patients. Health care systems worldwide are affected by increasing treatment
numbers and the costs involved. The treatment of nAMD constitutes an achievement for modern medicine. However, despite the challenges, it must be evaluated and reviewed repeatedly in order
to provide the best therapy for patients.
VO2peak Response Heterogeneity in Persons with Multiple Sclerosis: To HIIT or Not to HIIT?
Authors: Lea Schlagheck Marit , Wucherer Anika , Rademacher Annette , Joisten Niklas , Proschinger Sebastian , Walzik David , Bloch Wilhelm , Kool Jan , Gonzenbach Roman , Bansi Jens , Zimmer Philipp
Published: July 2021

Exercise is described to provoke enhancements of cardiorespiratory fitness in persons with Multiple Sclerosis (pwMS). However, a high inter-individual variability in training responses has been observed. This analysis investigates response heterogeneity in cardiorespiratory fitness following high intensity interval (HIIT) and moderate continuous training (MCT) and analyzes potential predictors of cardiorespiratory training effects in pwMS. 131 pwMS performed HIIT or MCT 3–5x/ week on a cycle ergometer for three weeks. Individual responses were classified. Finally, a multiple linear regression was conducted to examine potential associations between changes of absolute peak oxygen consumption (absolute ∆V̇O2peak/kg), training modality and participant’s characteristics. Results show a time and interaction effect for ∆V̇O2peak/kg. Absolute changes of cardiorespiratory responses were larger and the non-response proportions smaller in HIIT vs. MCT. The model accounting for 8.6% of the variance of ∆V̇O2peak/kg suggests that HIIT, younger age and lower baseline fitness predict a higher absolute ∆V̇O2peak/kg following an exercise intervention. Thus, this work implements a novel approach that investigates potential determinants of cardiorespiratory response heterogeneity within a clinical setting and analyzes a remarkable bigger sample. Further predictors need to be identified to increase the knowledge about response heterogeneity, thereby supporting the development of individualized training recommendations for pwMS.
Selbstinduzierte epileptische Anfälle Prävalenz,
Ursachen und Behandlung
Authors: Rösche Johannes , Dudek Maria Iracema Rocha , Kohnen Oona
Published: July 2021

Die Erstbeschreibung selbstinduzierter epileptischer Anfälle stammt von
1827. Die Prävalenz wird von der Mehrzahl der Autoren bei 1%
unselektierter Patienten mit Epilepsie angege-ben. Dabei machen die Patienten
meist etwa ein Viertel der Patienten mit photosensibler Epilepsie aus. Es sind
daneben jedoch auch viele nicht-visuelle Auslösemechanismen beschrieben.
Die Ursachen können in angenehmen Empfindungen während der
ausgelösten Anfälle oder einer spannungslösenden
Funktion der Anfälle bestehen. Häufig wird das
Selbstinduktionsmanöver als unwillkürlicher Vorgang erlebt. Die
Behandlung erweist sich insgesamt als schwierig. Für einzelne Patienten
sind positive Effekte einer Verhaltenstherapie beschrieben. Bei photosensiblen
Epilepsien wird die Abschottung von den auslösenden Reizen durch
Sonnenbrillen empfohlen. Unter pharmakologischen Therapien scheinen Fenfluramin,
Clonazepam und Valproat am aussichtsreichsten. Der Erfolg hängt
unabhängig von der Methode stark von der
Veränderungsbereitschaft der Patienten ab.
Das subgaleale Hämatom beim Neugeborenen – ein
neonatologischer Notfall
Authors: Andresen Felicia , Zieger Barbara , Würtemberger Urs , Kunze Mirjam , Hentschel Roland
Published: July 2021

Das subgaleale Hämatom (SGH) ist eine seltene Geburtskomplikation des
Neugeborenen und kann aufgrund des erheblichen Blutverlustes in den subgalealen
Raum zu einem hämorrhagischen Schock führen. Wir berichten von
zwei Neugeborenen, die ein subgaleales Hämatom mit schwerem
hämorrhagischem Schock und Enzephalopathie entwickelten. Im ersten Fall
eines reifen weiblichen Neugeborenen wurde die Entstehung des subgalealen
Hämatoms durch eine Neugeboreneninfektion und die Geburt mittels
Vakuumextraktion begünstigt. Der zweite Fall eines männlichen
Frühgeborenen wurde durch eine schwierige Kindsentwicklung mittels
sekundärer Sectio caesarea kompliziert. Neben der raschen Behandlung des
Schocks ist vor allem die Therapie der Gerinnungsstörung essentiell.
Beide Fälle verdeutlichen, dass das subgaleale Hämatom ein
neonatologischer Notfall ist.
Perioperative Management of Pediatric Patients with Moyamoya Arteriopathy
Authors: Gardner Yelton Sarah E. , Williams Monica A. , Young Mollie , Fields Jennifer , Pearl Monica S. , Casella James F. , Lawrence Courtney E. , Felling Ryan J. , Jackson Eric M. , Robertson Courtney , Scafidi Susanna , Lee Jennifer K. , Cohen Alan R. , Sun Lisa R.
Published: July 2021

Pediatric patients with moyamoya arteriopathy are at high risk for developing new onset transient or permanent neurologic deficits secondary to cerebral hypoperfusion, particularly in the perioperative period. It is therefore essential to carefully manage these patients in a multidisciplinary, coordinated effort to reduce the risk of new permanent neurologic deficits. However, little has been published on perioperative management of pediatric patients with moyamoya, particularly in the early postoperative period during intensive care unit admission. Our pediatric neurocritical care team sought to create a multidisciplinary periprocedural evidence- and consensus-based care pathway for high-risk pediatric patients with moyamoya arteriopathy undergoing anesthesia for any reason to decrease the incidence of periprocedural stroke or transient ischemic attack (TIA). We reviewed the literature to identify risk factors associated with perioperative stroke or TIA among patients with moyamoya and to gather data supporting specific perioperative management strategies. A multidisciplinary team from pediatric anesthesia, neurocritical care, nursing, child life, neurosurgery, interventional neuroradiology, neurology, and hematology created a care pathway for children with moyamoya undergoing anesthesia, classifying them as either high or standard risk, and applying an individualized perioperative management plan to high-risk patients. The incidence of neurologic sequelae before and after pathway implementation will be compared in future studies.
Enhancement of the coloring invariant for folded molecular chains
Authors: Ceniceros Jose , Elhamdadi Mohamed , Mashaghi Alireza
Published: July 2021

Folded linear molecular chains are ubiquitous in biology. Folding is mediated by intra-chain interactions that “glue” two or more regions of a chain. The resulting fold topology is widely believed to be a determinant of biomolecular properties and function. Recently, knot theory has been extended to describe the topology of folded linear chains, such as proteins and nucleic acids. To classify and distinguish chain topologies, algebraic structure of quandles has been adapted and applied. However, the approach is limited as apparently distinct topologies may end up having the same number of colorings. Here, we enhance the resolving power of the quandle coloring approach by introducing Boltzmann weights. We demonstrate that the enhanced coloring invariants can distinguish fold topologies with an improved resolution.
The Cauchy problem for the fourth-order Schrödinger equation in H
s
Authors: Liu Xuan , Zhang Ting
Published: July 2021

We consider the fourth-order Schrödinger equation i∂tu + Δ2u + μΔu + λ|u|αu = 0 in HsRN, with N≥1,λ∈C, μ = ±1 or 0, 0 < s < 4, 0 < α, and (N − 2s)α < 8. We establish the local well-posedness result in Hs(RN) by applying Banach’s fixed-point argument in spaces of fractional time and space derivatives. As a by-product, we extend the existing H2 local well-posedness results to the whole range of energy subcritical powers and arbitrary λ∈C.
High-purity solid parahydrogen
Authors: Bhandari Ashok , Rollings Alexandar P. , Ratto Levi , Weinstein Jonathan D.
Published: July 2021

Alkali atoms trapped in solid hydrogen matrices have demonstrated ultralong electron spin coherence times and are promising as quantum sensors. Their spin coherence is limited by magnetic noise from naturally occurring orthohydrogen molecules in the parahydrogen matrix. In the gas phase, the orthohydrogen component of hydrogen can be converted to parahydrogen by flowing it over a catalyst held at cryogenic temperatures, with lower temperatures giving a lower orthohydrogen fraction. In this work, we use a single cryostat to reduce the orthohydrogen fraction of hydrogen gas and grow a solid matrix from the resulting high-purity parahydrogen. We demonstrate the operation of the catalyst down to a temperature of 8 K, and we spectroscopically verify that orthohydrogen impurities in the resulting solid are at a level <10−6. We also find that, at sufficiently low temperatures, the cryogenic catalyst provides isotopic purification, reducing the HD fraction.
Write-once-read-many-times resistive switching behavior of amorphous barium titanate based device with very high on-off ratio and stability
Authors: Shringi Amit Kumar , Betal Atanu , Sahu Satyajit , Kumar Mahesh
Published: July 2021

Write once read many times (WORM) memory devices based on the resistive switching mechanism of a sputtered amorphous BaTiO3 (am-BTO) thin film in a metal–insulator–metal structure is fabricated on a FTO coated glass substrate with a silver top contact. Fabricated devices show the switching from a low-conductance state to a high-conductance state with the formation of conductive filament(s) in the am-BTO layer. The memory characteristics are investigated as a function of thickness of am-BTO layer, which is determined by varying the deposition time. Devices with all deposited thicknesses show data retention for more than 4000 s and 300 reading cycle. Devices with 180 nm thickness show a high on-off ratio on the order of 106. The fabricated WORM devices exhibit good reading-endurance and data-retention characteristics.
Multi-stroke anti-hysteresis algorithm based on inverse model
Authors: Fan Wei , Fu Yuchen , Zhu Laifa , Yang Jianhong
Published: July 2021

The control strategy of multi-stroke repetitive driving is often required in the micro–nano-system. However, the current research only focuses on the modeling algorithm of a single stroke; thus, it is difficult to realize the hysteresis compensation at any stroke of the piezoelectric actuator. This paper proposes a multi-stroke compensation algorithm combined with the inverse model: through the analysis of the hysteresis model, the rising trajectory with better linearity is defined as the target line to find a mathematical expression with fewer parameters to describe the falling trajectory, then to find the relationship between maximum stroke voltage and the above parameters to establish a mathematical model that can describe any stroke, and finally, to verify that the above model applies to any unknown stroke, thereby realizing multi-stroke compensation. The experimental results show that the hysteresis corrected rate after the above algorithm compensation is mostly over 85%, of which the maximum hysteresis corrected rate is 93.81% and the hysteresis error is less than 2.5%. Experiments prove the effectiveness of the above multi-stroke compensation algorithm based on the inverse model and extend the research on piezoelectric hysteresis characteristics to multi-stroke compensation.
The stress in a dispersion of mutually polarizable spheres
Authors: Reed K. M. , Swan J. W.
Published: July 2021

Dispersions of dielectric and paramagnetic nanoparticles polarize in response to an external electric or magnetic field and can form chains or other ordered structures depending on the strength of the applied field. The mechanical properties of these materials are of interest for a variety of applications; however, computational studies in this area have so far been limited. In this work, we derive expressions for two important properties for dispersions of polarizable spherical particles with dipoles induced by a uniform external field—the isothermal stress tensor and the pressure. Numerical calculations of these quantities, evaluated using a spectrally accurate Ewald summation method, are validated using thermodynamic integration. We also compare the stress obtained using the mutual dipole model, which accounts for the mutual polarization of particles, to the stress expected from calculations using a fixed dipole model, which neglects mutual polarization. We find that as the conductivity of the particles increases relative to the surrounding medium, the fixed dipole model does not accurately describe the dipolar contribution to the stress. The thermodynamic pressure, calculated from the trace of the stress tensor, is compared to the virial expression for the pressure, which is simpler to calculate but inexact. We find that the virial pressure and the thermodynamic pressure differ, especially in suspensions with a high volume fraction of particles.
Enhancement of photoelectron emission efficiency from quantum dot solids, through electrical field biasing of interfaces
Authors: Eshraghi K. , Bandaru P. R.
Published: July 2021

It is shown through comparison with experimental results that the efficiency of quantum dot (QD) film-based photoemission would be impacted by an inadequate supply of electrons from an electron source. An explanation for the related photocurrent droop, as arising from restricted electron transmission at the substrate-QD interface as well as between the QDs, is proposed. It is suggested that interfacial potential based biasing schemes could considerably enhance electronic coupling for improved transmission and quantum efficiency. Modeling indicates that electric fields of ∼450 MV/m would be necessary for ensuring electron transmission coefficients close to unity.
Ferroelectric domain evolution in a Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 piezoceramic studied using piezoresponse force microscopy
Authors: Jiang Xijie , Dietz Christian , Liu Na , Rojas Virginia , Stark Robert W.
Published: July 2021

Lead-free Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-0.5BCT) ceramics have drawn attention in recent years because of their outstanding dielectric and electromechanical properties, such as a piezoelectric coefficient d33 ∼ 620 pC N−1 and a large signal of d33* ∼ 1100 pm V−1 at 0.5 kV mm−1 at room temperature (RT). These particular properties are relevant to a range of applications. However, the structural origin of this high piezoelectric coefficient is still a subject of discussion. An in-depth understanding of the ferroelectric domain evolution of BZT-0.5BCT ceramics is crucial for probing the underlying mechanisms and for guiding practical applications. Using piezoresponse force microscopy (PFM), we have directly visualized the evolution of the BZT-0.5BCT domain structure using temperature and electric field stimulation on micrometer and nanometer scales. The PFM results unambiguously evidence the coexistence of wedge-shaped and lamellar domains with miniaturized nanodomain structures at RT. The temperature- and electric-field-dependent PFM study presented here highlights the critical role of wedge-shaped domains in domain evolution. Wedge-shaped domains turn into small domains with curved domain walls after the heating cycle and then become lamellar domains after the poling cycle at RT. Transitional domain structures with an increased density of nanodomains appear in both the thermal and poling cycles. More interestingly, the electric-field-dependent domain structure evolution at different temperatures shows better domain structure reversibility at high temperatures than at temperatures close to the phase boundary. This demonstrates that the BZT-0.5BCT ceramic has superior stability at medium temperatures (40 °C–60 °C), implying excellent stability for applications.
Electronic and geometric structure of cationic and neutral chromium and molybdenum ammonia complexes
Authors: Jackson Benjamin A. , Miliordos Evangelos
Published: July 2021

High level quantum chemical approaches are used to study the geometric and electronic structures of M(NH3)n and M(NH3)n+ (M = Cr, Mo for n = 1–6). These complexes possess a dual shell electronic structure of the inner metal (3d or 4d) orbitals and the outer diffuse orbitals surrounding the periphery of the complex. Electronic excitations reveal these two shells to be virtually independent of the other. Molybdenum and chromium ammonia complexes are found to differ significantly in geometry with the former adopting an octahedral geometry and the latter a Jahn–Teller distorted octahedral structure where only the axial distortion is stable. The hexa-coordinated complexes and the tetra-coordinated complexes with two ammonia molecules in the second solvation shell are found to be energetically competitive. Electronic excitation energies and computed IR spectra are provided to allow the two isomers to be experimentally distinguished. This work is a component of an ongoing effort to study the periodic trends of transition metal solvated electron precursors.
Deep learning-based statistical noise reduction for multidimensional spectral data
Authors: Kim Younsik , Oh Dongjin , Huh Soonsang , Song Dongjoon , Jeong Sunbeom , Kwon Junyoung , Kim Minsoo , Kim Donghan , Ryu Hanyoung , Jung Jongkeun , Kyung Wonshik , Sohn Byungmin , Lee Suyoung , Hyun Jounghoon , Lee Yeonghoon , Kim Yeongkwan , Kim Changyoung
Published: July 2021

In spectroscopic experiments, data acquisition in multi-dimensional phase space may require long acquisition time, owing to the large phase space volume to be covered. In such a case, the limited time available for data acquisition can be a serious constraint for experiments in which multidimensional spectral data are acquired. Here, taking angle-resolved photoemission spectroscopy (ARPES) as an example, we demonstrate a denoising method that utilizes deep learning as an intelligent way to overcome the constraint. With readily available ARPES data and random generation of training datasets, we successfully trained the denoising neural network without overfitting. The denoising neural network can remove the noise in the data while preserving its intrinsic information. We show that the denoising neural network allows us to perform a similar level of second-derivative and line shape analysis on data taken with two orders of magnitude less acquisition time. The importance of our method lies in its applicability to any multidimensional spectral data that are susceptible to statistical noise.
Enhanced sound focusing with single-slit lens
Authors: Chen Jian , Zhang Mengru , Chen Yuanliu , Ju Bingfeng , Fan Zheng
Published: July 2021

Sound transmission efficiency and beaming capability are the most important considerations in the design of single-slit lens toward high-performance acoustic imaging and detection. Here, we demonstrated numerically and experimentally enhanced sound focusing through a single subwavelength slit surrounded by grooves on both surfaces. A microscopic coupled-wave model was employed to optimize the slit-groove structure for both transmission enhancement and beam focusing. The simulated and measured results were in good agreement and readily verified the effectiveness of the proposed method in enhancing sound focusing with a single-slit lens. This work paves an alternative avenue for the design of single-slit lens, which may find potential applications in the broad field of acoustics, such as tumor boundary treatment, edge detection, and subwavelength acousto-optic modulation.
Universities ramp up efforts to improve faculty gender balance and work climate in STEM
Authors: Feder Toni
Published: July 2021

Small actions can cumulatively lead to big advances.
Transforming Australia's approach to decommissioning research
Authors: Taylor Andrew , Macreadie Peter I.
Published: July 2021

In 2018, Australian oil and gas (O&G) operators committed funds to a collaborative approach to research to improve the evidence base for O&G decommissioning decisions. This followed an unsuccessful bid to establish a cooperative research centre for decommissioning. Modelled on the INSITE North Sea program, the National Decommissioning Research Initiative (NDRI) was established for an initial period of 3 years, until July 2022, with funding of $3.4 million. Research is focused on understanding the impact that full removal or in situ decommissioning may have on the marine environment. The program is supported by Woodside Energy, Santos Limited, BHP, Chevron Australia, ExxonMobil, Shell Australia and Vermilion Oil and Gas Australia and managed by National Energy Resources Australia. This study describes the establishment of the NDRI and expected future developments.
A new engagement approach for regulatory submissions
Authors: Arnott James , Wilson Ben , Kurz Daniel
Published: July 2021

As a business strategy, Australian Gas Infrastructure Group (AGIG) has sought to leverage leading practices associated with stakeholder engagement to underpin the development of its submitted Access Arrangement Plan for 2021–2025 to the Economic Regulation Authority (ERA). The approach focused on developing a plan that would deliver for current and future customers and was capable of being accepted by all customers and stakeholders. The plan involved building an engagement model around six endorsed engagement principles that delivered a ‘no surprises’ outcome. This included active engagement with customers and stakeholders through a series of planned roundtables – commencing 14 months prior to formal submission. The process also included processes, structures and communication channels that supported group and one-on-one engagement and feedback sessions against a tightly managed timeline and the use of an online engagement platform. The extended abstract includes company representatives from AGIG and the stakeholder group (NewGen Power) reflecting on the process, engagement principles, leading practices adopted and lessons learnt through the engagement process.
How the upstream oil and gas industry can leverage interdisciplinary research to more effectively engage with Indigenous communities
Authors: Lockhart Deborah , Xu Jessica
Published: July 2021

Since 2010, mining companies have requested permission for the destruction of over 463 Aboriginal heritage sites. Recent high-profile events have profoundly impacted culturally significant Indigenous sites, and mining companies are under intense pressure to demonstrate greater sensitivity in their relationships with stakeholders. The Australian Disputes Centre uses several case studies to explore how the upstream petroleum industry can leverage current interdisciplinary research to engage with Indigenous communities more effectively, both nationally and internationally. Interest-based negotiation frameworks are considered as actionable mechanisms that are as applicable in day-to-day business operations as they are in supporting consistent, culturally-sensitive stakeholder agreements. The application of a range of communication strategies and skills to harness intersectional decision-making is reviewed, and asks the extent to which engagement with external stakeholders reflects internal corporate culture. Obtaining and retaining a social licence to operate is top of mind for all resource companies, but it does not come without a congruent culture of principled negotiation. This study considers the emerging challenges within the sector, including how to empower all parties to negotiate more fulsome outcomes. Using various case studies, including one involving the conservation of submerged Indigenous heritage, an holistic, interdisciplinary methodology for managing cross-cultural sensitivities while companies undertake technical investigations, liaise with archaeological and ethnographic experts and negotiate with local community leaders has been reviewed. Clearly, inclusive communication is just the beginning.
The Australian CCS roadmap – a reflection on lessons learned and considerations for future success
Authors: Paz Jerome
Published: July 2021

With the announcement of the Australian government’s technology roadmap ‘out of COVID’, we are on the cusp of potentially the next wave of carbon, capture and sequestration (CCS) project development. To date, Australia has just one operational large-scale CCS project. Before Australia embarks on a potential new wave of CCS developments, reflection on successes and the lessons learned both domestically and in a global context is required. Xodus has reviewed a range of CCS projects, taking into consideration project type, government policy, investment and country energy mix. From this, Xodus has assessed what is needed to enable deployment of large-scale CCS projects.
Biology and conservation of the unique and diverse halophilic macroinvertebrates of Australian salt lakes
Authors: Lawrie Angus D’Arcy , Chaplin Jennifer , Pinder Adrian
Published: July 2021

This study synthesises information on the biology of the unique and diverse halophilic macroinvertebrates of Australian salt lakes, focusing on gastropods and crustaceans. This information is needed to evaluate and manage the threats posed to these invertebrates by increased periods of drought and secondary salinisation. Most of these species are endemic to Australian salt lakes, and some have adapted to extreme conditions (e.g. salinities >100 g L–1 and pH <5). This study identifies key general findings regarding the taxonomy, ecology and life histories of these invertebrates, such as that many ‘new’ species have been uncovered in the past 20 years, with more likely to come. The study also identifies critical knowledge gaps, such as the need to elucidate the abiotic and biological drivers of the field distributions of species, including why some species are widespread and common whereas other congeneric species are rare or have narrow distributions. Those species that are either restricted to low salinity environments or survive dry periods as aestivating adults (as opposed to desiccation-resistant eggs) are probably the most vulnerable to increasing salinisation and drought. Future work should prioritise the development of a sound taxonomy for all groups, because this is needed to underpin all other biological research.
Ultrasound-on-chip platform for medical imaging, analysis, and collective intelligence
Authors: Rothberg Jonathan M. , Ralston Tyler S. , Rothberg Alex G. , Martin John , Zahorian Jaime S. , Alie Susan A. , Sanchez Nevada J. , Chen Kailiang , Chen Chao , Thiele Karl , Grosjean David , Yang Jungwook , Bao Liewei , Schneider Rob , Schaetz Sebastian , Meyer Christophe , Neben Abraham , Ryan Bob , Petrus J. R. , Lutsky Joe , McMahill Dan , Corteville Gregory , Hageman Matthew R. , Miller Larry , Fife Keith G.
Published: July 2021

Significance

Affordable hand-held ultrasound is transforming health care as a diagnostic tool with the potential to be as ubiquitous as the stethoscope. Here, we present a platform for advancing diagnostic care consisting of an ultrasound-on-chip probe, leveraging state-of-the-art silicon-based semiconductor foundries, paired with a mobile device and artificial-intelligence–guided image interpretation and cloud interconnectivity. Demonstrations across key organs and modes illustrate the imaging capabilities. Presentations of automated guidance for untrained ultrasound users show the potential for further broadening accessibility and utility.