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The present article examines the micropolar fluid flow with nanofluid suspension across porous stretching/shrinking surfaces with added heat transfer through heat source/sink and radiation. The situation arises in the electrolytic fluid flow across fuel-cell membranes in advanced batteries or fuel cells. To understand the flows and the efficacy of the fuel cell, we study the fluid dynamics of the flow across such shrinking/stretching membranes by converting the non-dimensional governing partial differential equations to ordinary differential equations by using suitable similarity transforms. The energy equation is then analytically solved using hypergeometric series. It is noted that there is a lack of study on nanofluids in the circumstances of micropolar and radiation with porous media. The novelty of the present problem is to examine the influence of micropolar nanofluid flow with heat transfer over permeable surfaces. Analyses show that increasing the rate of shrinking/stretching boundary and increasing the Darcy number decreases the velocity of the fluid while increasing the Eringen number decreases the skin friction decreases dramatically, and increasing the thermal radiation and heat source/sink parameters enhances the thermal boundary layer. Other variations of parameters are also studied and explained graphically. The current work has many useful implications in efficient fuel-cell developments, developing nanofluid has significantly improved the heat transmission process for manufacturing with applications in engineering, biological, and physical sciences. • The present article studies the micropolar nanofluid flow across porous surfaces. • Heat transfer was studied by adding radiation to the energy equation. • Temperature increases due to rising the values of volume fraction. • Momentum and energy equations contain velocity slip and temperature jump boundary conditions. • Both momentum and energy equations are solved analytically. [ABSTRACT FROM AUTHOR]

Unlike in controlled settings, social scientists' performance when predicting real-world societal trends is indistinguishable from that of laypeople or naive statistical methods. There is no conclusive evidence that domain-specific expertise improves predictive accuracy of societal change. Causal models in social sciences are oversimplified, confusing levels of analysis, and generally lack specificity about the magnitude or distribution of effects, limiting prediction accuracy. Engaging in counterfactual thought experiments to go beyond the most obvious factors specified in a theory, predictive accuracy in social sciences can be improved. Integrating broad foundational models with context-specific time series data, as in meteorology, can enhance the accuracy of social science predictions. Enhancing analytical training and understanding of temporal dynamics can yield more precise, riskier predictions, the practical application of which requires the fostering of intellectual humility in scientists. We examine the opportunities and challenges of expert judgment in the social sciences, scrutinizing the way social scientists make predictions. While social scientists show above-chance accuracy in predicting laboratory-based phenomena, they often struggle to predict real-world societal changes. We argue that most causal models used in social sciences are oversimplified, confuse levels of analysis to which a model applies, misalign the nature of the model with the nature of the phenomena, and fail to consider factors beyond the scientist's pet theory. Taking cues from physical sciences and meteorology, we advocate an approach that integrates broad foundational models with context-specific time series data. We call for a shift in the social sciences towards more precise, daring predictions and greater intellectual humility. [ABSTRACT FROM AUTHOR]

Physics is a field of science that has traditionally used the scientific method to answer questions about why natural phenomena occur and to make testable models that explain the phenomena. Discovering equations, laws, and principles that are invariant, robust, and causal has been fundamental in physical sciences throughout the centuries. Discoveries emerge from observing the world and, when possible, performing interventions on the system under study. With the advent of big data and data-driven methods, the fields of causal and equation discovery have developed and accelerated progress in computer science, physics, statistics, philosophy, and many applied fields. This paper reviews the concepts, methods, and relevant works on causal and equation discovery in the broad field of physics and outlines the most important challenges and promising future lines of research. We also provide a taxonomy for data-driven causal and equation discovery, point out connections, and showcase comprehensive case studies in Earth and climate sciences, fluid dynamics and mechanics, and the neurosciences. This review demonstrates that discovering fundamental laws and causal relations by observing natural phenomena is revolutionised with the efficient exploitation of observational data and simulations, modern machine learning algorithms and the combination with domain knowledge. Exciting times are ahead with many challenges and opportunities to improve our understanding of complex systems. [ABSTRACT FROM AUTHOR]

Dust accumulation is one of the critical issues that must be mitigated on in-situ lunar explorations because an in-situ probe is exposed to small dust particles, which are easily attached to it, during its operations. The Lunar Dust Science Definition Team is organized by the Jet Propulsion Lab/California Institute of Technology through NASA's Biological and Physical Sciences Division to define key science questions and assess dust remediation techniques. Here, we assess three electrostatic remediation technology concepts: electrostatic dust shield; surface electrostatically collecting dust, later called attractive surface; and electron beam — plasma jet inducing electrostatic dust lofting from a surface. We qualitatively investigate their maturity by defining six operational factors: Time and location; Amount of dust removal; Contamination of target surfaces; Operation duration; Installation; and Safety. In addition to these techniques, we discuss a supporting system that loads dust particles onto a test article to examine dust removal efficiency. The results show that further development increases the maturity of all the technologies. While laboratory and theoretical demonstrations reported whether each technology robustly work on the Moon, which hosts a complex, heterogeneous dust environment, we find that it is still uncertain if this is the case because none has been tested in the lunar environment. Particularly, operation duration and safety are critical to be addressed further on both laboratory and spaceflight scales. • We assess three dust mitigation technologies for in-situ lunar explorations. • Six operational factors are considered to qualitatively assess their maturity. • Further assessment sheds light on how mitigation technologies work on the Moon. • Operation duration and safety are key to improving dust mitigation technologies. • We also introduce a dust loading device that supplies dust to a testbed in situ. [ABSTRACT FROM AUTHOR]

The motivation of the current paper is to provide a detailed review of crucial topics in micro- and nanoscale gas flows, i.e., velocity slip and temperature jump phenomena and their modeling, Knudsen minimum, and thermally-driven flows with application in Knudsen pumps. Non-equilibrium gas flows at the micro and nano scales exhibit peculiarities different from the intuition of macroscopic continuum fluid dynamics and heat transfer. Rarefied gas flows experience unique features such as slip and jump boundary effects , Knudsen paradox , pumping effect , , anti-Fourier heat transfer , thermal critical Knudsen number , and rarefied gas shock polars. This paper reviews the latest advancements and investigations on the gas–surface velocity and temperature inequalities, named velocity slip and temperature jump , in rarefied gas flows. Thermodynamic non-equilibrium effects are localized in the Knudsen layer within a width of a few gas mean free path near the surfaces. These particular features result in inequalities between the velocity and temperature of the gas concerning the surface. Experimental investigations of the slip and jump conditions from the first observation to the recent studies are reviewed. Next, a comprehensive review of the different categories of velocity slip models from the Maxwell model up to the recently developed models will be performed. For the first time, all the current models on the viscosity of rarefied gas are classified and compared in the present paper. Progress in the derivation of the models describing the temperature jump of rarefied gas over a solid surface will be performed. Next, a unique behavior of rarefied gas named the Knudsen paradox or Knudsen minimum is introduced and reviewed based on the different viewpoints. Different possible reasons for the origin of the Knudsen paradox phenomena are reviewed. A complete set of experimental and numerical works which detected the Knudsen paradox feature will be historically reviewed. Then, the closed-form relations obtained from the numerical simulations and experimental measurements indicating and predicting the occurrence of the Knudsen paradox phenomenon are reviewed and compared. The end section of this paper focuses on deemed physical and real-world applications of the rarefied flows at small scales utilizing thermally driven gas flows, i.e., the pumping effect of the rarefied gas. The pumping effect of the rarefied gas under temperature gradient leads to the Knudsen pump or Knudsen compressor concept. The main advantage over macro-scale pumps is that these sorts of pumps do not suffer from reduced life cycles due to various modes of mechanical failure because they do not have any rotating and moving parts. Moreover, the pumps mentioned above could find applications in gas chromatography, spectroscopy, moving gases on a chip, forced convection cooling, and micro-nano scale actuators. Different classes of thermally-induced flows with their origins are proposed and discussed, containing the recently detected thermally-driven flows. Based on that, a critical and comprehensive review of the different types and configurations of Knudsen pumps will be presented in detail. The newest published research containing new designs of Knudsen pumps has been considered in this review. Different numerical techniques developed or employed to simulate Knudsen pumps will be extensively reviewed. Besides, all published experimental investigations on Knudsen pumps will be reviewed and classified. Overall, this review will provide insights into the emerging physical science and engineering application of micro- and nanoscale gas flows. [ABSTRACT FROM AUTHOR]

A dual-coolant integrated experimental facility named DRAGON-V has been developed at the Institute of Nuclear Energy Safety Technology, Hefei Institute of Physical Science, Chinese Academy of Sciences, for the key technology research and performance evaluation of candidate liquid lithium-lead (PbLi) blanket of hydrogen fusion reactors. The loop is composed of a material test sub-loop and thermal-hydraulic test sub-loop, the design parameters are PbLi inventory 20 tons, PbLi temperature up to 550 °C, the maximum PbLi flow rate up to 40 kg/s. A novel cold trap system is designed to remove the suspended and crystalized impurities in PbLi fluid with three cooling zones and cross row arrangement of rod bundle filter elements. The paper describes the loop itself and its major components, initial loop testing, flow and measurement diagnostics and current experiments. The obtained test results of the loop and its components have demonstrated that the new facility is fully functioning and ready for experimental studies of material corrosion with/without a magnetic field, magnetohydrodynamic (MHD) effect, purification, heat and mass transfer phenomena in PbLi flows and can also be used in mock-up testing in conditions relevant to fusion applications. • A lithium-lead facility with 40 kg/s mass flow and 2–5 T magnetic field was built. • The composition and performance of the device are described and tested in detail. • A novel cold trap system with three cooling zones has been designed and proposed. • The safety analysis of loss of flow accident and loss of heat sink was investigated. [ABSTRACT FROM AUTHOR]

The UK's Engineering and Physical Sciences Research Council supported a series of meetings in 2021 to develop a roadmap for future research in Quantitative Modelling in Cleaning and Decontamination. Quantitative modelling in this context is the development of numerical and predictive tools, based on scientific principles, which can support design, operation and decision making associated with cleaning and decontamination. The activity involved identifying past and current activities on this topic across a range of different fields, including food and drink, consumer goods, healthcare, pharmaceuticals, nuclear, civil defence and biofilms. Input was received from operators, manufacturing companies, government agencies and researchers. The exercise identified a series of common needs which span sectors, and the challenges which need to be addressed to facilitate transfer of knowledge between sectors and develop the expertise required to tackle new challenges including those posed by sustainability. [ABSTRACT FROM AUTHOR]

The connection between biomedical science and space technology has historically been very strong and often led to significant scientific/technological evolutions. The ISS has been for years the perfect environment to study and test many biomedical applications. Long duration space travels need further development of reliable, portable and miniaturised medical support systems. In recent years there has been an increase in the number of space start-ups/spin-offs specifically dedicated to health, with the aim of commercialising the results of research. For example, the use of Carbon Nanotubes (CNT) to treat brain tumours, fibre optic probes to detect cataracts, or the development of wearable devices for clinical and leisure use. We review the devices for cardiovascular control and how space scientific and technological experiments contributed to the evolution of terrestrial applications and vice-versa. For a systematic approach, we combined the standardised taxonomy of ESA Technology Tree, which provides a classification of all technological expertise available for space activities, with the Italian National Classification of Medical Devices (the CND). In particular, we focused on technologies related to Life & Physical Science, Environmental Control Life Support (ECLS) and In-Situ Resource Utilisation (ISRU). The CND taxonomy is also aligned with the existing relevant classifications at the International level, such as the Global Medical Device Nomenclature (GMDN). By using specific keywords, our review considers both patent and scientific literature data (2010–2020) on cardiovascular control devices for space applications as well as space developments that may have contributed to the improvement of terrestrial activities. We analysed global trends, International Patent Classifications (IPC), country distributions, top assignees and funding sponsors. As a result, we identified that both scientific literature and patents have witnessed a general increase for the period under examination. China and the United States maintain the leading positions in both scientific literature and patenting publications. Similarly, European community member States (particularly Germany, Italy, Spain and France) and United Kingdom are very active. The most recurring technological protected domains include diagnosis, surgery, measurement and pharmaceuticals technologies. Therefore, patent and literature indicators, integrated with market information, provide a clear assessment of the related technology trends and readiness levels. • Connection between biomedical and space research has historically been strong. • Combination of ESA Technology Tree with the Classification of Medical Devices. • Cardiac functions monitoring is fundamental for astronauts and on Earth. • Literature review of devices developed for space and used on earth or viceversa. • Patent analysis of biomedical/cardiocirculatory devices for space applications. [ABSTRACT FROM AUTHOR]

Since the last century, the abundance of MXenes, two-dimensional (2D) transition-metallic carbides/nitrides isolated from multilayer MAX states, has gained considerable attention in the research of 2D transitional metallic borides. Researchers originally described a novel class of 2D transition metallic borides as MXene precursors in 2017 and gave these the fast moniker MBenes. MBenes have garnered significant attention in the fields of nanotechnology, physical science, and chemistry during the last five years. MBenes have a potential prospect, because they possess numerous appealing features and are being extensively explored for energy conservation and electrocatalysis purposes. However, the research study of MBene is still in its initial phases, presenting numerous predicted characteristics and impacts that have yet to be examined. Similarly, the computational predictions and primary experimental efforts reveal the extensive chemistry, exceptional reactions, substantial mechanical properties, high electrical conductance, transitional features, and potential for energy capturing of these materials. MBenes have a higher range of structural complexity in comparison to MXenes, since they possess various crystallography configurations, polymorphism, and undergo structural transitions. These characteristics complicate the process of synthesizing and separating them into single flakes. This review initially provides a comprehensive overview of MBenes, describing them as a collection of 2D transition metallic borides, that have sandwich-like structures formed from multilayer MAB phases. Next, we discussed the advancement of synthesis techniques, characteristics, distinctive properties, morphology, and potential applications of MBenes for energy conservation and electrocatalysis processes. The continuous challenges with performing experimental synthesis and making computational predictions were thoroughly discussed, along with the potential and future possibilities of MBenes. [Display omitted] • MBenes originated from 2D transition metallic borides organized in a sandwich-like structure. • MBene have multilayer MAB phases have been thoroughly analyzed. • Synthesis techniques, geometries, properties, and key parameters of MBenes has been discussed. • Potential applications of MBenes for energy conservation has been discussed. • Lastly, the future challenges in experimental and computational analysis of MBenes, has been discussed. [ABSTRACT FROM AUTHOR]

Introduction: Wire guided localization has been widely utilized as the standard method of pre-operative localization of breast lesions. Magnetic seeds were developed to counter some of the disadvantages associated with wires. This aim of this study was to assess outcomes following the introduction of magnetic seeds at a tertiary specialist breast centre.Methods: A retrospective review of a prospective database of the first 100 patients who underwent magnetic seed (Magseed) guided breast surgery between November 2018 and November 2019. Data was collected from 17 wire guided cases completed during the trial phase for comparison. The primary outcome measures were successful excision of index lesion and retrieval of the magnetic seed. Secondary outcomes analyzed included time ready for theatre, post-operative complications and breast margin re-excision rate.Results: Of these 100 cases, 85 patients underwent Magseed guided wide local excision for invasive or in-situ carcinoma and 15 underwent Magseed guided diagnostic excision. The primary lesion was excised, and Magseed was retrieved in all 100 cases. 54% of patients were ready to proceed as the first scheduled theatre case of the day, compared to 0% of wire-guided cases. Amongst therapeutic Magseed guided cases, the re-excision rate for margin clearance was 9.4%.Conclusion: Magseed guided breast excision is a new technology that has been implemented with relative ease in our unit. We have shown that magnetic seed guided surgery reliably localizes lesions, is associated with low re-excision rates without an increase in patient morbidity or mortality and results in improvements in theatre planning and efficiency. [ABSTRACT FROM AUTHOR]

Interaction of two solitons with different structures is exhibited. By adjusting the corresponding parameters, distinct solitons and their interaction can be achieved. It can also simulate a process of energy concentration of solitons at different times. [Display omitted] • We investigated a two-dimensional Gross-Pitaevskii equation with time-varying trapping potential in the Bose-Einstein condensation. • The Hirota bilinear method is established to solve the two-dimensional Gross-Pitaevskii equation and its parabolic soliton, line-soliton and dromion-like structure can be exhibited via some appropriate parameters chosen. Their interaction structures are discussed. • The interaction of two-soliton solutions is investigated through asymptotic analysis. The Gross-Pitaevskii equation is a class of the nonlinear Schrödinger equation, whose exact solution, especially soliton solution, is proposed for understanding and studying Bose-Einstein condensate and some nonlinear phenomena occurring in the intersection field of Bose-Einstein condensate with some other fields. It is an important subject to investigate their exact solutions. We give multi-soliton of a two-dimensional Gross-Pitaevskii system which contains the time-varying trapping potential with a few interactions of multi-soliton. Through analytical and graphical analysis, we obtain one-, two- and three-soliton which are affected by the strength of atomic interaction. The asymptotic expression of two-soliton embodies the properties of solitons. We can give some interactions of solitons of different structures including parabolic soliton, line-soliton and dromion-like structure. By constructing an appropriate Hirota bilinear form, the multi-soliton solution of the system is obtained. The soliton elastic interaction is analyzed via asymptotic analysis. The results in this paper theoretically provide the analytical bright soliton solution in the two-dimensional Bose-Einstein condensation model and their interesting interaction. To our best knowledge, the discussion and results in this work are new and important in different fields. The study enriches the existing nonlinear phenomena of the Gross-Pitaevskii model in Bose-Einstein condensation, and prove that the Hirota bilinear method and asymptotic analysis method are powerful and effective techniques in physical sciences and engineering for analyzing nonlinear mathematical-physical equations and their solutions. These provide a valuable basis and reference for the controllability of bright soliton phenomenon in experiments for high-dimensional Bose-Einstein condensation. [ABSTRACT FROM AUTHOR]

Background: Women have been observed to have a higher risk of developing posttraumatic stress symptoms (PTSS) after disaster compared to men. In a study of survivors of an earthquake, we sought to investigate: whether there was differential exposure to disaster-related trauma by gender; whether women and men have differential vulnerability to trauma; and what factors could explain the gender difference in PTSS.Methods: Data from a cohort of community-dwelling older survivors of the 2011 Great East Japan Earthquake and Tsunami was used. Data were obtained before (2010) and 2.5-years after the disaster (n = 3,334).Results: Women suffered 1.6 times higher prevalence of PTSS than men (31.0% vs. 19.4%). Women were more likely to experience loss of relatives (29.2% vs. 23.2%), while men were more likely to report loss of friends (17.1% vs. 14.5%) and separation from work (7.5% vs. 4.6%). We did not find evidence for differential vulnerability to disaster-related trauma. Indeed, the gender gap in PTSS was larger among individuals who did not experience trauma. Women experienced greater deterioration of non-kin instrumental support, which significantly mediated the association between gender and PTSS.Limitations: We have no information on PTSS prior to the earthquake. Nor do we have clinician diagnoses of PTSD.Conclusions: Women experienced housing damages and loss of relatives more often than men, which explained ∼21% of the gender gap in PTSS after disaster. Women reported more non-kin support prior to the disaster, but they also experienced greater deterioration of it, which explained ∼21% of the gender gap. [ABSTRACT FROM AUTHOR]

• Hybrid nano fluid flow over permeable stretching/shrinking surface. • Nonlinear PDEs are converted into dimensionless ODEs by using similarity variable. • Radiation and heat source/sink effect included in the temperature equation. • Characteristics of physical parameters are described graphically. • While increase the magnetic field parameter skin friction also increases. The present study examines the effect of radiation and inclined magnetic field on the biviscosity Bingham hybrid nanofluid flow on the permeable stretching/shrinking surface. Hybrid nano fluid composites are formed by dissolving Graphene oxide (GO) and Molybdenum disulfide (MoS 2) in base fluid Ethylene Glycol (EG), applying these nanoparticles to the Ethylene Glycol (base fluid) will enhance heat transfer. Furthermore, it studied the heat transmission process using variable thermal conductivity of the heat source/sink. Governing equations of velocity and temperature are converted to a set of nonlinear ordinary differential equations (ODE) via suitable transformations and the obtained equations are solved using the boundary conditions, energy equation with radiation, and heat source/sink effect solved analytically by using hypergeometric function. Significant physical characteristics like mass transpiration, Prandtl number, Biot number, and thermal radiations can be discussed using the graphical analysis. The investigation outcomes reveal that increasing the magnetic field enhances skin friction. Increasing the volume fraction, Biot number, and thermal radiation increases the thermal boundary layer, and velocity decreases by increasing the inverse Darcy parameter. Current work has many useful applications in engineering, biological and physical sciences, cleaning engine lubricants, thrust bearing technologies, etc. [ABSTRACT FROM AUTHOR]

[Display omitted] • Landscape evolution often occurs via bioengineering activities of interacting species. • We simulated the spatial relationships among pocket gophers, plants, and landforms. • The animals modified soil and vegetation, which in turn increased gopher fitness. • This three-way coevolutionary feedback was maintained and reinforced in the model. Landscape evolution is often driven by the bioengineering activities of multiple species interacting with one another, which modify the Earth's surface topography and processes. In this study, we used a spatially explicit, individual-based simulation model to investigate potential biogeomorphological coevolutionary feedback relationships. Specifically, we examined how pocket gophers, grassland vegetation, and associated bioengineered soil landscapes may co-define and co-adjust with each other. The model used in this study was parameterized to represent a hypothetical grassland ecosystem typical of those found in California, USA. We found that, as pocket gopher preference for annual plants increased, (i) the number of mounds constructed by these animals increased, (ii) the length of the burrow systems increased, (iii) the complexity of the burrow systems increased, and (iv) the area supporting perennial plants decreased. Collectively, these results would lead to greater food availability (i.e., annual plants) and a more favorable habitat for foraging, breeding, raising offspring, and evading predators. Therefore, the emerging habitat conditions engineered by pocket gophers are expected to eventually enhance their fitness when they increasingly burrow under areas dominated by annual vegetation. As traits associated with preference for annual plants are favored and passed on to future generations, a reinforcing feedback loop between preference for annuals and gopher fitness is anticipated to develop and persist over evolutionary timescales. Our model provides a comprehensive overview by integrating three types of selection pressures: environmental conditions, species interactions, and habitat conditions modified by multiple coevolving engineer species. We anticipate that this study will motivate geoecologists, evolutionary biologists, and geomorphologists to expand their focus beyond their traditional domains within the biological and physical sciences, encouraging exploration of the integrative discipline of biogeomorphology. [ABSTRACT FROM AUTHOR]

The number of intramedullary procedures to treat leg length discrepancy (LLD) has risen in the past decade and this has led to increased complications such as nail breakage. The aim of this study was to reveal our experience with implant failure after externally magnetic-controlled telescopic bone lengthening. We observed nail-breakage in 4 out of 24 patients (16.7%) after 6 to 15 months (median 13.5 months) following lower limb lengthening for LLD due to non-union or insufficient bone healing. Three femora and one tibia were treated in one posttraumatic and three congenital cases. Three out of the four patients had an elevated Charleston Comorbidity Index (CCI). Revision surgery involved removal of the broken nail and implantation of a trauma nail. At final follow-up all patients showed subjective satisfaction, achievement of desired lengthening with complete bone healing. Based on our results no unequivocal risk factor including number of previous surgeries, comorbidities and age was identified. In cases of delayed bone formation, early revision surgery with an exchange to a trauma nail has to be considered to prevent breakage of the intramedullary telescopic device. [ABSTRACT FROM AUTHOR]

• Beneficial NPs bring about useful morpho-physiological, biochemical and molecular alterations. • Beneficial NPs impart positive effect on plant growth and enhance abiotic stress tolerance. • Wider usage of beneficial NPs for crop improvement and abiotic stress management is highly endorsed. Nanoparticles (NPs) possess specific physical and chemical features and they are capable enough to cross cellular barriers and show their effect on living organisms. Their capability to cross cellular barriers have been noticed for their application not only in medicine, electronics, chemical and physical sciences, but also in agriculture. In agriculture, nanotechnology can help to improve the growth and crop productivity by the use of various nanoscale products such as nanofertilizers, nanoherbicides, nanofungicides, nanopesticides etc. An optimized concentration of NPs can be administered by incubation of seeds, roots, pollen, isolated cells and protoplast, foliar spraying, irrigation with NPs, direct injection, hydroponic treatment and delivery by biolistics. Once NPs come in contact with plant cells, they are uptaken by plasmodesmatal or endocytosed pathways and translocated via apoplastic and / symplastic routes. Once beneficial NPs reach different parts of plants, they boost photosynthetic rate, biomass measure, chlorophyll content, sugar level, buildup of osmolytes and antioxidants. NPs also improve nitrogen metabolism, enhance chlorophyll as well as protein content and upregulate the expression of abiotic- and biotic stress-related genes. Herein, we review the state of art of different modes of application, uptake, transport and prospective beneficial role of NPs in stress management and crop improvement. [ABSTRACT FROM AUTHOR]

Speed of sound and attenuation are essential for characterizing reference materials such as biological tissue-mimicking materials (TMMs) used in ultrasonic applications. There are many publications on the manufacture of TMMs and the measurement of their properties. However, no studies in the literature have applied the metrological approach of International Organization for Standardization (ISO) Guide 35 to certify biological ultrasound TMMs as candidates for reference materials (RMs). The work described here was aimed at studying the process for manufacturing fat, muscle and aorta artery TMMs, including the study of the homogeneity, stability, trend and characterization of TMMs. The properties of interest were the speed of sound (SoS) and attenuation coefficient (AttC) at 7.5 MHz, with target expanded uncertainty of 40 m/s and 0.3 dB/cm, respectively. The short-term stability study was 2 mo at 4°C and 40°C (simulating possible transportation conditions). The long-term stability study lasted an additional 4 mo with the TMM at 22°C (simulating possible storage conditions). Homogeneity was evaluated before the stability study. Uncertainties associated with homogeneity, stability, characterization and trend were duly calculated. No trend was observed in this study, but the AttC spread widely during the stability test, substantially enlarging the final uncertainty. Therefore, this property could not be used to certify TMM candidates as RMs. However, the SoSs for most TMMs lay within the target uncertainty, disclosing viability to certify TMMs as RMs for this property. Assigned values for SoS were 1560 m/s for aorta TMM with an average expanded uncertainty for certificate validity of 12 mo (Ue;12=20 m/s), 1552 m/s for muscle TMM (Ue;12=20 m/s) and 1494 m/s for fat TMM (Ue;12=11 m/s). Thus, TMMs were proved suitable to be certified as RMs for SoS. [ABSTRACT FROM AUTHOR]

Pursuing topological phases in natural and artificial materials is one of the central topics in modern physical science and engineering. In classical magnetic systems, spin waves (or magnons) and magnetic solitons (such as domain wall, vortex, skyrmion, etc.) represent two important excitations. Recently, the topological insulator and semimetal states in magnon- and soliton-based crystals (or metamaterials) have attracted growing attention owing to their interesting dynamics and promising applications for designing robust spintronic devices. Here, we give an overview of current progress of topological phases in structured classical magnetism. We first provide a brief introduction to spin waves and their band structure in periodic lattices. Then, we elaborate typical topological invariants and pedagogical models that are important to understand the topological nature of magnons, such as the magnon Hall effect, topological magnon insulators, Dirac (Weyl) magnon semimetals, topological magnon polarons (magnon–phonon​ hybrid excitations), and higher-order topological magnons. Appealing proposal of topological magnonic devices is also highlighted. We then review the collective-coordinate approach for describing the dynamics of magnetic soliton lattice. We focus on the topological properties of magnetic solitons, by theoretically analyzing the first-order topological insulating phases in low dimensional systems and higher-order topological states in breathing crystals. Finally, we discuss the experimental realization and detection of the edge states in both magnonic and solitonic crystals. We remark the challenges and future prospects before concluding this article. [ABSTRACT FROM AUTHOR]

Using blood speckle tracking (BST) based on high-frame-rate echocardiography (HFRE), we compared right ventricle (RV) flow dynamics in children with atrial septal defects (ASDs) and repaired tetralogy of Fallot (rTOF). Fifty-seven children with rTOF with severe pulmonary insufficiency (PI) (n = 21), large ASDs (n = 11) and healthy controls (CTL, n = 25) were included. Using a flow phantom, we studied the effects of imaging plane and smoothing parameters on 2-D energy loss (EL). RV diastolic EL was similar in ASD and rTOF, but both were greater than in CTL. Locations of high EL were similar in all groups in systole, occurring in the RV outflow tract and around the tricuspid valve leaflets in early diastole. An additional apical early diastolic area of EL was noted in rTOF, corresponding to colliding tricuspid inflow and PI. The flow phantom revealed that EL varied with imaging plane and smoothing settings but that the EL trend was preserved if kept consistent. [ABSTRACT FROM AUTHOR]

Expanding the role of Space Physical Science and Technology in the modern world comes through the application of digital technologies and supercomputing. The present paper is aimed at getting the readers acquainted with results of resent scientific discussions on the topic having taken place at specialized scientific forums supported by the International Academy of Astronautics. The paper provides a breath coverage of results of main discussions and current trends in developing modern digital approach to solving acute problems of Space Physical Science and Technology. Numerical simulations with massive parallelization have natural limitation of efficiency. The results of recent studies demonstrate that each algorithm has an optimal number of parallel threads providing maximal efficiency. On further increasing the number of parallel processes, one encounters a decrease of efficiency. The universal supercomputers can hardly provide high efficiency in solving multi-scale problems. Creating supercomputers of a specialized architecture focused on a narrow class of multiscale problems will allow for efficient parallel solution of such problems. • Protection of Space structures from space debris collisions and micrometeoroids. • Fire safety of Space vehicles and Propulsion systems. • Supercomputer predictive modeling for ensuring Space program safety. • Each algorithm has an optimal number of parallel threads providing maximal efficiency. [ABSTRACT FROM AUTHOR]

Geo-Spatial Technology and Applications (GSTA) contributes significantly to the implementation of the UN 2030 Agenda for Sustainable Development, which seeks to 'leave no one behind'. This study attempts to assess the gender diversity in enrolment in GSTA programmes in developing countries in Asia using data available with the UN-affiliated Regional Centre in India. A survey was also conducted to gauge trainees' comfort in a complex multi-cultural, multi-linguistic classroom environment. The analysis shows that female participation in short-term courses has been increasing rather steeply over the years (1995–2019). The enrolment has reached 30% in recent years. It is also observed that the female participants have preferred (about 10%) to enrol in physical Science and Technology (ST) -oriented courses such as Remote Sensing and GIS, Satellite Meteorology and Climate Change, and Space and Atmospheric Sciences when compared to electrical Engineering and Technology-oriented Satellite Communications and Global Navigation Satellite Systems courses that would require a strong knowledge of digital signals and systems theory. The survey study with a participation of 150 trainees from 17 countries shows that women trainees have a slight edge by 9% over the male counterparts in learning ST elements of the courses. At sub-regional levels, it is observed that participants from Indian sub-continent countries (ISC) are better by 15% than participants from South-east Asian Countries (SAC) and Central Asian Countries (CAC). As far as the course structure perspective is concerned, there has been a significant difference with 70% of the ISC trainees have found the courses as well-balanced covering equally both technology and applications, while only 36% and 56% of the trainees from SAC and CAC, respectively, have found the course as balanced. Importantly, the survey has revealed that the participants from SAC and CAC have a big challenge in apprehending lectures in English, as reflected by their top scores at 18% and 17%, respectively, compared with the corresponding value of the ISC trainees being 72%. Recommendations are suggested to sustain the female enrolment in long-term GSTA training programmes. Strategies that create family-friendly learning conditions, including joint education programmes involving lead institutions of the participants' countries, are proposed to facilitate higher female participation. Furthermore, measures such as standardisation of curricula regionally at undergraduate levels and having periodic meetings of trainers are recommended in order to minimise the trainees' core competency gaps in GSTA disciplines at the regional level. [ABSTRACT FROM AUTHOR]

Recently, a 4th-order asymptotic preserving multiderivative implicit-explicit (IMEX) scheme was developed [28]. This scheme is based on a 4th-order Hermite interpolation in time, and uses an approach based on operator splitting that converges to the underlying quadrature if iterated sufficiently. Hermite schemes have been used in astrophysics for decades, particularly for N-body calculations, but not in a form suitable for solving stiff equations. In this work, we extend the 4th-order scheme to higher orders. Such high-order schemes offer advantages when one aims to find high-precision solutions to systems of differential equations containing stiff terms, which occur throughout the physical sciences. We begin by deriving Hermit schemes of arbitrary order and demonstrating how the 4th-order IMEX method generalises in a straightforward manner to any of these schemes. Afterwards, we discuss the stability of Hermite schemes, and prove convergence properties of the corresponding IMEX methods. We then present results for methods ranging from 6th to 12th order and explore a selection of test problems, including both linear and nonlinear ordinary differential equations as well as Burgers' equation. To our knowledge this is also the first time that Hermite time-stepping methods have been applied to partial differential equations. We then discuss some benefits of these schemes, such as their potential for parallelism and low memory usage, as well as limitations and potential drawbacks. [ABSTRACT FROM AUTHOR]

Despite the growth of interest in the phenomenon of shell-nounhood in academic discourse, research has been primarily concerned with published research articles. This contrasts with the limited attention that it has received in the study of disciplinary student writing. This study explores discipline specificity in student writing through an in-depth multifaceted analysis of two frequent shell nouns, problem and way , in a sample of Year 3 undergraduate native writing from the British Academic Written English (BAWE) corpus in three disciplines: Sociology, Business and Engineering. The lexical, syntactico-semantic and textual variables coded yield results that conform to the divide between the more experimental approach of the Physical Sciences and the more interpretive one taken in the Social Sciences. The examination of data in this paper helps identify distinctive disciplinary trends at various levels of linguistic analysis, many of which could then be further inspected through more automated pattern-driven investigations of larger datasets. • Use of both nouns reflects broader differences between hard and soft disciplines. • Problem use in Engineering is more compressed and technical than way use. • Problem and way use in Business resembles use in Sociology and Engineering. • Problem and way use in Sociology is more elaborated, discursive and evaluative. [ABSTRACT FROM AUTHOR]

Beginning with the marginalist revolution of the late nineteenth century, neoclassical economic theory developed by borrowing mathematical constructs from physics, but not the physics itself. Several scholars, including early ecological economists, recognized there was a need to incorporate energy and other resources into economic theory. In recent decades there have been attempts to fuse energy into aggregate neoclassical production functions, but these suffer from several challenges: they do not hold at an aggregate level; do not capture the dynamic evolution of the economy; ignore the universal flow of energy through all of the economy; and there is interdependency between variables. These challenges are largely addressed by energy-linked computable general equilibrium models, although their model formulations still understate the role of energy as the lifeblood of economies. Here I argue that the economy can simultaneously be studied in terms of physical units and monetary units. I contrast physical science and social science views on energy in economies, and demonstrate how thermodynamics and value theory can be used harmoniously with an example of the energy basis to capital formation in the United States. When used to study major transformation of energy systems, equations, or metrics, are required for each type of energy carrier in the economy. • Natural and social science perspectives on energy in economies are contrasted. • Economic activities should be simultaneously expressed in physical and monetary terms. • Energy is a conserved physical quantity, not a measure of value nor a metaphor. • Energy can be universally used to describe all physical activities in an economy. • An example shows value theory and thermodynamics can be combined in harmony. [ABSTRACT FROM AUTHOR]

• W segregates strongly into ZrB 2 grain boundaries even at elevated temperatures. • W segregation strengthens ZrB 2 grain boundaries, improving strength of ZrB 2. • Grain boundary segregation promotes grain boundary selection during heat treatment. • Machine learning potential pushes accurate atomistic simulation to high temperatures. • Accurate deep learning potential for Zr 1-x W x B 2 system is firstly fitted. Interaction between grain boundaries and impurities usually leads to significant altering of material properties. Understanding the composition-structure-property relationship of grain boundaries is a key avenue for tailoring and designing high performance materials. In this work, we studied segregation of W into ZrB 2 grain boundaries by a hybrid method combining Monte Carlo (MC) and molecular dynamics (MD), and examined the effects of segregation on grain boundary strengths by MD tensile testing with a fitted machine learning potential. It is found that W prefers grain boundary sites with local compression strains due to its smaller size compared to Zr. Rich segregation patterns (including monolayer, off-center bilayer, and other complex patterns); segregation induced grain boundary structure reconstruction; and order-disorder like segregation pattern transformation are discovered. Strong segregation tendency of W into ZrB 2 grain boundaries and significant improvements on grain boundary strengths are certified, which guarantees outstanding high temperature performance of ZrB 2 -based UHTCs. [ABSTRACT FROM AUTHOR]

Volume assessment of abdominal aortic aneurysms (AAAs) using 3-D ultrasound (US) is an innovative technique reporting good agreement with computed tomography angiography. One major limitation of the current 3-D US technique is a limited field of view, allowing full AAA acquisition in only 60% of patients. This study presents two new US acquisition protocols using magnetic field tracking, providing an "extended field of view" (XFoV-2-D and XFoV-3-D) with the aim of including both the aortic bifurcation and neck for full-volume assessment, and compares these methods with the current standard 3-D US protocol and with computed tomography angiography. A total of 20 AAA patients were included and underwent the current standard 3-D US protocol and the two novel 3-D US "extended field of view" protocols. Four patients were excluded from further analysis because of low image quality, leaving 16 patients eligible for analysis. Full AAA volume was achieved in 8 patients (50%) using the standard 3-D US protocol, in 11 patients (69%) with the XFoV-2-D protocol and in 13 patients (81%) with the XFoV-3-D protocol. In conclusion, this article describes two new and feasible US protocols applicable for full-AAA-volume estimation in most patients and should initiate further research into the added value of full volume in AAA surveillance. [ABSTRACT FROM AUTHOR]

It has been proved that the reactive elements improve the adhesion strength of the α-Al 2 O 3 /β-NiAl interface significantly, and Hf may be the best choice among the common doping elements, including Hf, Zr, Dy, Y, La for the interface without impurity. However, when impurity sulfur has to be considered, it is found that La and Y enhance interface adhesion and mechanical stability strength of α-Al 2 O 3 /β-NiAl–S interface most obviously, rather than Hf. The fundamental mechanism of reactive elements tying up S in the interface and the selection of reactive elements have been studied via a combinational analysis of bond topology and electronic structure. [ABSTRACT FROM AUTHOR]

This manuscript, divided into two parts, provides a contextual and historiographical analysis of Edwin Arthur Burtt's classic The Metaphysical Foundations of Modern Physical Science. My discussion corroborates the sparse technical literature on Burtt (Moriarty 1994; Villemaire, 2002), positioning his work in the aftermath of American idealism and the rise of realist, pragmatist and naturalist alternatives. However, I depart from the existing interpretations both in content and focus. Disagreeing with Moriarty, I maintain that Burtt's Metaphysical Foundations is not an idealist work. Moreover, I provide an alternative to Villemaire's mainly Deweyite/pragmatist reading, emphasizing the import of new realism and naturalism. Burtt's historical thesis should not be viewed as outlining a systematic philosophical position, but rather as a (coherent) culmination of numerous philosophical problematics. To support my conclusion, I provide a substantial summary of Burtt's text alongside a contextual analysis of the philosophical issues that preoccupied his teachers and peers in Columbia's philosophy department. I conclude with a historiographical section, rendering explicit the connections between Burtt's understanding of the scientific revolution, and his distinctive early 20th century American intellectual context. • Contextualises a classic historical account of the Scientific Revolution. • Elaborates on key publications from Columbia's philosophy department during 1902–1926. • Outlines key incidents in the historical development of American realism and pragmatism. • Integrates the history of science, the philosophy of science, and the history of philosophy. [ABSTRACT FROM AUTHOR]

This manuscript, divided into two parts, provides a contextual and historiographical analysis of Edwin Arthur Burtt's classic The Metaphysical Foundations of Modern Physical Science. My discussion corroborates the sparse technical literature on Burtt (Moriarty, 1994; Villemaire, 2002), positioning his work in the aftermath of American idealism and the rise of realist, pragmatist and naturalist alternatives. However, I depart from the existing interpretations both in content and focus. Disagreeing with Moriarty, I maintain that Burtt's Metaphysical Foundations is not an idealist work. Moreover, I provide an alternative to Villemaire's mainly Deweyite/pragmatist reading, emphasizing the import of new realism and naturalism. Burtt's historical thesis should not be viewed as outlining a systematic philosophical position, but rather as a (coherent) culmination of numerous philosophical problematics. To support my conclusion, I provide a substantial summary of Burtt's text alongside a contextual analysis of the philosophical issues that preoccupied his teachers and peers in Columbia's philosophy department. I conclude with a historiographical section, rendering explicit the connections between Burtt's understanding of the scientific revolution, and his distinctive early 20th century American intellectual context. • Contextualizes a classic historical account of the Scientific Revolution. • Elaborates on key publications from Columbia's philosophy department during 1902–1926. • Outlines key incidents in the historical development of American realism and pragmatism. • Integrates the history and historiography of science, the history of philosophy and the philosophy of science. [ABSTRACT FROM AUTHOR]

Defect evolution under irradiation is investigated in a set of single-phase concentrated solid solution alloys (SP-CSAs) containing Ni with Co, Fe and/or Cr. We show that atomic segregation of Ni takes place already at very early stages of radiation damage in the 2–4 element SP-CSAs containing Fe or Cr, well below 1 dpa. We arrive at this conclusion by following the evolution of positron annihilation signals as a function of irradiation dose in single crystal samples, complemented by molecular dynamics simulations in the same model systems for high entropy alloys (HEAs). This manifestation of short-range order calls attention to composition fluctuations at the atomic level in irradiated HEAs. Ion irradiation may induce short-range order in certain alloys due to chemically biased elemental diffusion. The work highlights the necessity of updating the assumption of a totally random arrangement in the irradiated alloys, even though the alloys before irradiation have random arrangements of different chemical elements. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Background: As many local municipality and medical workers were involved in disaster recovery duties following the Great East Japan Earthquake (GEJE) on March 11, 2011, the aim of this work was to elucidate the distinct trajectories for post-traumatic stress disorder (PTSD) symptoms and associated factors among these personnel. They confronted a diverse range of stressors both as survivors and as relief workers; however, little is known about their longitudinal PTSD symptoms.Methods: The participants were 745 local municipality and hospital medical workers [average age: 43.6 ± 9.5 years, range: 20 - 66 years; 306 (59%) women] involved in disaster recovery duties following the GEJE. PTSD symptoms were measured using the Japanese version of the PTSD Checklist Specific Version (PCL-S) at four time points: 14, 30, 43, and 54 months after the GEJE. Using group-based trajectory modeling, distinct trajectories were elucidated.Results: We identified five distinct PTSD symptoms profiles: resistance (n = 467, 62.7%), subsyndromal (n = 181, 24.3%), recovery (n = 47, 6.3%), fluctuating (n = 26, 3.5%), and chronic (n = 24, 3.2%). The trajectories differed according to the post-disaster working conditions and personal disaster experiences.Limitations: Potential selection bias resulting from the limited number of participants who completed all waves. The survey was conducted in one region of the disaster area.Conclusions: The majority of participants remained stable, with a relatively small group classified as chronic and fluctuating. Our results highlight the importance of improved working conditions and sustained monitoring of workers responding to natural disasters. [ABSTRACT FROM AUTHOR]

To apply an existing transport model to industrially relevant granular mixtures and flows, we demonstrate an approach to experimentally measure the segregation coefficient, S , and the flowing layer thickness, δ , using a modified quasi-2D bounded heap. During heap formation, the flowing layer velocity is characterized using particle image velocimetry, which determines δ and other kinematics. After formation, the heap is sampled to determine the concentration of each species along its length. The difference between measured and model-predicted concentration profiles is minimized by varying S , which gives the experimental estimate of S for the mixture of interest. The methodology is tested for bidisperse combinations of Cellets — industrially relevant and roughly spherical microcrystalline-cellulose particles. Variation of S with particle-size-ratio matches previous DEM results for glass particles. Further validation of the approach is provided by tests with different flow rates and mixtures, including glass particles and Cellets, and a tridisperse Cellets mixture. Unlabelled Image • Granular flow segregation parameter estimated from quasi-2D heap flow experiments. • Estimated segregation parameter agrees with directly measured value from simulation. • Estimated parameter accurately predicts segregation in other flows and mixtures. [ABSTRACT FROM AUTHOR]

We present a method to estimate the segregation parameter, S , a key input in a continuum transport model of particulate flows. S is determined by minimizing the difference between measured and model-predicted concentration profiles. To validate the approach, we conduct discrete element method simulations of size-bidisperse mixtures in quasi-2D bounded heap flow; the resulting data show that S calculated from concentration profiles is consistent with the directly measured value. The method's accuracy depends critically on the velocity profile during filling, but only weakly on the diffusion coefficient. When the velocity profile is nominally spanwise invariant, the error between estimated and measured S is 10%. This method is intended for practical application (described in Part II), so we restrict characterization of the velocity profile to that which can be readily determined experimentally, and explore the sensitivity of concentration profiles to variation of the gap between the sidewalls of the heap. Unlabelled Image • Estimate model segregation parameter from measured particle concentration profiles. • Matching model-predicted profiles to measured profiles yields segregation parameter. • Narrow quasi-2D heap geometry eliminates spanwise flow and concentration variation. [ABSTRACT FROM AUTHOR]

Interfacial solute segregation behavior of P in nanocrystalline (NC) Ni alloys is investigated at the atomic scale using cross-correlative PED-APT measurements and atomistic simulations. Inhomogeneous P-segregation in grain boundaries (GBs) of NC Ni is observed from both experimental measurements and simulation calculations. Interfacial excess (IE) of the solute within GBs is further studied as function of GB misorientation. Significant scatter is detected in the IE of boundaries with similar misorientation angles and even within special boundaries with identical Σ values. From atomistic simulations, a general trend of increasing IE with initial GB energy and volume is observed but with poor correlation, indicating that the segregation behavior cannot be captured with a single average measure of the entire GB character. Rather the results suggest that the extent of interfacial solute segregation correlates better with fraction of high energy atomic sites in the boundary. By comparing IE values with thermodynamic model predictions, it is shown that the interfacial segregation behavior is strongly influenced by the energy distribution of atomic sites in the GBs. However, in order to predict the extent of solute segregation, the evolution of the atomic energy landscape in the GB with continuous solute segregation must be considered. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Background: Urinary incontinence is especially common in older age. Non-pharmacological therapies are particularly desirable in this group.Objective: To define optimal evidence-based non-pharmacological, non-surgical therapies for urinary incontinence in older persons.Methods: A Delphi process determined critical outcome measures of interest. Studies of any non-pharmacological intervention reporting critical outcomes were identified through database searches for relevant systematic reviews in Medline, Embase, CINAHL, PsycInfo and Cochrane up to June 2018. Primary trials with a population mean age ≥65years were identified, from which data were extracted and risk of bias was assessed. Qualitative analysis and meta-analysis, when possible, were undertaken, followed by grading of the evidence using GradePro software. Finally, bullet-point recommendations were formulated for the indications and contraindications for non-pharmacological interventions for urinary incontinence in older persons.Results: Frequency of incontinence was identified as a critically important outcome. In total, 33 systematic reviews were identified with 27 primary trials meeting inclusion criteria. Evaluated therapies included exercise therapy, habit retraining, behavioural therapy, electrical stimulation, transcutaneous tibial nerve stimulation, magnetic stimulation, caffeine reduction and acupuncture. From meta-analysis, group exercise therapy and behavioural therapy in women were beneficial in reducing episodes of incontinence (mean reduction of 1.07 (95 %CI 0.69-1.45) and 0.74 (95 %CI 0.42-1.06) episodes per day respectively, evidence grade 'moderate'). Evidence for other interventions was limited and of insufficient quality.Conclusions: There is sufficient evidence to warrant recommendation of group exercise therapy for stress incontinence and behavioural therapy for urgency, stress or mixed urinary incontinence in older women. Evidence was insufficient to recommend any other non-drug therapy. [ABSTRACT FROM AUTHOR]

Background: Magnetic Seizure therapy (MST) is an emerging treatment for major depressive disorder (MDD) that is associated with fewer cognitive side effects compared to electroconvulsive therapy. The present pilot study sought to investigate whether daily MST treatments were associated to antidepressant effect and assess cognitive side effects associated with an accelerated MST (aMST) treatment schedule.Methods: Fifteen MDD patients underwent a six-day course of MST treatment to the vertex following assessment of symptom severity and neuropsychological testing. The primary outcome was severity on the Hamilton Rating Scale for Depression 17-item (HRSD-17). Patient also underwent neuropsychological assessment with the RBANS and Stroop Colour-Word test.Results: There were no instances of delirium or disturbance of consciousness following aMST sessions. Patients showed significant decreases on indices of depression and anxiety symptoms, with 9 (60%) patients showing a clinical response and 7 (47%) patients experiencing remission. Significant improvements were reported in RBANS total score, as well as indices of immediate memory and delayed memory. No changes at follow-up were reported for visuospatial/constructional, language, and attention RBANS indices, nor for Stroop Colour/Word performance.Limitations: The results should be interpreted with caution as they are part of a non-randomized, open-label pilot study. Further, the short duration of the study does not provide longitudinal follow-up to determine whether treatment response lasts a meaningful duration of time.Conclusions: aMST well tolerated without significant evidence of cognitive side effects and rapid improvement in symptoms. Further research is required to fully characterize these changes and replicate them in independent samples. [ABSTRACT FROM AUTHOR]

Alkali metals Na, K, Rb and Cs are depleted in planetary mantles and their depletion is commonly attributed to the effect of volatility during the condensation of the first solids in the solar nebula or the high temperatures involved during planetary growth. Most models of planetary differentiation assume that alkalis behave entirely as lithophile elements and do not participate in core segregation. Here, we tested this hypothesis by determining experimentally the partitioning of Na, Cs and Rb between iron sulfide and silicate (D sulf/sil) and combining it with available data from the literature on K, Na and Cs partitioning. Our experiments were conducted at 1–3.5 GPa, with an additional one at 8 GPa, 1600–1900 °C, and varying FeO contents, which lead to a relatively large range of O content in the sulfide phases (up to 13 wt%). We found maximum D sulf/sil of 0.8, 0.4, and 0.36 for Na, Cs and Rb respectively. In addition, D sulf/sil for Na, K, Cs and Rb increases with temperature and O content in the sulfide and decreases with FeO content in the silicate. The degree of polymerization of the silicate melt and the S content of the sulfide additionally increase D sulf/sil for Na, K and Cs. Since the solubility of O in sulfides is correlated with the FeO content of the silicate and both have opposite effects on D sulf/sil , varying the oxidation state of equilibrating material does not significantly affect D sulf/sil , which is more controlled by the temperature of equilibration. We modeled core formation for Earth, Mars and asteroid Vesta, assuming that some of the accreted embryos contained immiscible sulfides, that segregated into planetary cores. Our results show that with such a scenario, significant amounts of Na, K, Cs and Rb were sequestered in planetary cores, leading to core/mantle distribution of alkalis between 4·10−5 and 0.15. The depletion of alkalis in the mantles of Earth, Mars and Vesta could have resulted from combined effects of volatility and core segregation, but are largely due to volatile depletion in the accreting materials. [ABSTRACT FROM AUTHOR]

A gradient nanostructured surface layer was formed in an Al–4 wt%Cu alloy processed by means of surface mechanical grinding treatment at liquid nitrogen temperature. Within the deformed surface layer, laminated structures with a wide range of thickness were formed. With a decreasing depth from the treated surface, lamellae thickness decreases accompanied by an increased fraction of high angle grain boundaries (HAGBs) from 10% to 70%. In the topmost surface layer, nanolaminated (NL) structures were found with an average thickness as small as 28 nm and a HAGB fraction of 70%. Composition analysis indicated that Cu atoms segregate at NL boundaries in the as-prepared sample, Cu concentration is about 3–4 times higher than that in the lattice. The obvious grain boundary (GB) segregation of Cu induced by cryogenic plastic deformation is attributed dynamic interaction between solute atoms with gliding dislocations. GB segregation of Cu is responsible for the stabilization of the NL structures with a much finer structural size than that in pure Al, resulting in higher hardness. The deformation-induced GB segregation provides an alternative strategy to achieving stable high strength nanostructures in Al alloys. Image, graphical abstract [ABSTRACT FROM AUTHOR]

We propose a model for predicting the depletion zone arising next to grain boundaries during non-equilibrium segregation. The model directly links to distribution of segregation energies as provided by atomistic simulations. We expose the theoretical framework based on the thermodynamic extremal principle and propose an efficient algorithm to solve the underlying equations. The example of the W-25at%Re is discussed to illustrate the main features of the model. Multi-component segregation kinetics is discussed for segregation of B, C, and N in Mo to illustrate site-competition scenarios. Comparison with earlier results obtained without depletion illustrates the importance of this effects. Finally the depletion zones along GBs are investigated for many different compositions to asses for which material composition and heat treatments they may be observed experimentally. We find that extended depletion zones arise for very small solute concentrations. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Electric field in the silo at different particle segregation degree was simulated. • The simulation was proved to be effective to predict the electric field. • Electric field of the segregation case was compared with that of the uniform case. • Particle segregation not only can increase electric field but also can reduce it. The cylindrical metal silo plays an important role in the industry for storing the product, while the undesired of electrostatic charge on the dielectric powder leads to dangerous electrostatic discharge and threatening human safety and causing a great economic loss. The aim of the study was to investigate the effect of the particle segregation on the electric field in the silo base on the electric field simulation. Three parameters were studied: large particle layer thickness fraction, small particle space charge density (ρ S) and large particle space charge density (ρ L). The effect of the particle segregation on the electric field in the silo was evaluated through comparing the electric field in the segregation case to that in the uniform case. The results showed that the particle segregation significantly affected the electric field in the silo. The space charge density of the small particle mainly influenced the electric field in the small particle layer, while that of the large particle had a significant effect on the electric field in the large particle layer. The particle segregation not only could increase the electric field strength but also could decrease the electric field, which was dependent on the relative magnitude of the large (| ρ L |) and small (| ρ S |) particle space charge density. Additionally, the relative growth rate (absolute value) of the maximum electric field strength increased with the increase of | ρ L - ρ S |. [ABSTRACT FROM AUTHOR]

• Rotation speed and friction of side walls significantly affect granular segregation. • Where the maximum granular temperature occurs and where particles separate coincide. • Double segregation effect (DSE) is found at Froude number (Fr) close to 1. Size-induced granular segregation was performed systematically and experimentally in an almost fully filled double-walled rotating drum at 10 different rotation speeds and two different side wall types. The motion of the granular materials was recorded using a high-speed camera for image analysis of particle segregation development in the drum. With continual tracking of the particle movements, the velocity, fluctuations, and granular temperatures were measured. The experimental results indicate that both rotation speeds and friction coefficient of side walls significantly affect segregation phenomena in binary-size mixture granular flows. The results demonstrate similar situations to the Brazil-nut effect and its reverse in the radial direction at either high or a low rotational speed (where the Froude number (Fr) is far from 1). At these instances, the maximum granular temperature occurs near the side walls. Specifically, a double segregation effect (DSE) is found at Froude number (Fr) close to 1. These results can be used in many industrial processes, for example, size grading of materials, screening of impurities, and different structures of functionally graded materials. Moreover, the maximum granular temperature occurs in the middle of the ring space. It causes small particles to move toward both side walls as it pushes bigger particles to accumulate in the middle of the ring space of rotating drum. [ABSTRACT FROM AUTHOR]

Although water quality from freshwater recreational aquatic environments (RAEs) has been long analyzed worldwide, little information is available about their sediments. The aim of this work was to study the physicochemical and bacteriological quality of water and sediment under different seasonal events. For that, Wierna River (WR) and General Belgrano reservoir (GB) were used as freshwater RAEs models. A total of 33 water and 33 sediment samples (15 from WR and 18 from GB from each phase) were collected and analyzed. Physicochemical variables in water (pH, turbidity, dissolved oxygen, temperature, conductivity, alkalinity, hardness) and sediments (organic matter, humidity, ash, and conductivity) were measured. For the bacteriological characterization, total aerobic mesophiles, total and thermotolerant coliforms, E. coli, enteroccocci, Salmonella spp., and Pseudomonas aeruginosa were evaluated using culture-based methods. Universal and human Bacteroides were also quantified by real-time PCR. Univariate (Kruskall-Wallis), bivariate (Spearman correlation), and multivariate (cluster analysis, principal component analysis) statistical techniques were applied for data analysis. All bacterial indicators were almost two-logs higher in sediments than in water, for both RAEs. Also, due to rainfall events and recreational activities, sediments were resuspended in surface water exceeding in most cases the limit values established by international regulation for bacteria. Significant correlation was observed between culturable bacteria and turbidity (p < 0.05) supporting this. We found that while physicochemical variables clustered samples by geographical location in water and sediments, microbiological aggrupation in water was mostly driven by seasonal events. No aggrupation was observed when using microbiological variables in sediments. Thus, geographical location, type of water and sediments, and seasonal events influenced on RAEs quality. Including sediment analysis during RAEs monitoring campaigns is essential as it will allow knowing the real health risk to which bathers are exposed and proposing solutions to mitigate it. [ABSTRACT FROM AUTHOR]

Rotating drums are widely used in industry for powder mixing, milling, coating and drying processes. Segregation is inevitable when using a rotating drum to mix granules differing in size, density or shape. Size segregation in rotating drums has received comprehensive studies over the past decades, but most of the studies concentrate on spherical particles. Particle shape, as one of the important particle properties, could affect size-induced segregation significantly. However, such an effect is still poorly understood. In this work, DEM is employed to study the radial segregation of binary-sized ellipsoidal particles in a rotating drum. The segregation patterns for both spheres and ellipsoids are presented and compared. The effects of aspect ratio, size ratio and rotating speed on the extent of segregation are investigated. Generally, large particles tend to segregate to the periphery of the bed, whereas small ones are accumulated in the core section. As particle aspect ratio deviates from unity, i.e. elongated or platy shape-type, the extent of segregation is reduced. Small ellipsoidal particles tend to be entrained by large ellipsoids causing less segregation. The decrease of size ratio of small to large particles does not necessarily lead to a higher segregation extent. The results also show that in rolling or cascading regimes, increasing the rotating speed can reduce the extent of segregation for both spheres and ellipsoids. The studies also indicate that the initial states of mixtures do not affect the final segregation patterns. Unlabelled Image • Size segregation of ellipsoids in rotating drums is investigated by DEM. • Ellipsoids have lower segregation extent than spheres in a steady state. • Increasing size difference does not necessarily cause a higher segregation extent. • Final segregation extent and segregation rate decrease with rotation speeds. • Initial states of mixtures do not affect the final segregation patterns. [ABSTRACT FROM AUTHOR]

In this research work, we constructed the solitary wave solutions of generalized Kadomtsev–Petviashvili modified equal width (KP-MEW) equation with the help of new technique which is modification form of extended auxiliary equation mapping method. The generalized KP-MEW equation is the nonlinear PDEs which described the propagation of long-wave with dissipation and dispersion in nonlinear media. As a result, families of solitary wave solutions are obtained in different form of solitons, bright–dark solitons and traveling wave solutions. The physical structure of these new solutions is shown graphically in two and three dimensions with the aid of computer software Mathematica. These obtained new solutions show the power and effectiveness of this new method. We can also solve other nonlinear system of PDEs which are involved in mathematical physics and many other branches of physical sciences with the help of this new method. [ABSTRACT FROM AUTHOR]

This work is motivated by the frequent occurrence of boundary value problems with various boundary conditions in the modeling of some problems in engineering and physical science. Here we propose a new technique to force the positive definite kernels such as some radial basis functions to satisfy the boundary conditions exactly. It can improve the applications of existing methods based on positive definite kernels and radial basis functions especially the kernel based pseudospectral method for handling the differential equations with more complicated boundary conditions. In the proposed technique some new kernels are constructed using the positive definite kernels in a manner that they satisfy the required conditions. In addition, we prove the positive definiteness of the newly constructed kernel, and also the non-singularity of the collocation matrix is proved under some conditions. The proposed method is verified through the numerical solution of some benchmark problems such as a singularly perturbed steady-state convection–diffusion problem, two and three dimensional Poissons equations with various boundary conditions. [ABSTRACT FROM AUTHOR]

• The strengthening of hypoeutectic silumin surface was performed by complex method. • The multiple increase in wear resistance of modified layer has been established. • The formation of multiphase submicro – nanodimentional states was revealed. The analysis of structure, phase composition and tribological properties of surface layers of hypoeutectic silumin after complex treatment including the electroexplosion alloying by yttrium oxide powder in different modes and subsequent electron beam processing was done by the methods of modern physical material science. The complex treatment is accompanied by the formation of multi–phase submicro – nanocrystalline layer up to 80 μm thick enriched by yttrium atoms and being responsible for the increase in wear resistance. It is shown that Y atom concentration in the modified layer depends on electroexplosion alloying (EEA) mode. The distribution of Y atoms in the layer depends on the mode of EEA as well. [ABSTRACT FROM AUTHOR]