Academic literature on the topic 'Virtual initial mass model'

Rotor imbalances have a significant impact on the level of their vibration and reliability. Reduction of rotor imbalances is achieved through static and dynamic balancing that we propose to accomplish by virtual balancing of rigid rotors in two stages. At the first stage mutual orientation of the rotor parts is calculated to compensate their imbalances and couple unbalance. At the second stage the values of the masses and angular coordinates of two correction weights that allow eliminating the residual imbalance of the rotor are determined. The correction weights are placed in two balancing planes of the rotor. A model of virtual balancing is proposed to implement the balancing stages. The model makes it possible to determine the relative angular positions of the rotor parts, the values of the mass of two correction weights and their angular coordinates in the balancing planes. The effectiveness of using the proposed model was verified by performing calculations using the finite element model (FEM) of the rotor in the ANSYS software package. In the course of the study, data were obtained on the values of vibration velocities on the rotor supports. The results obtained show a significant reduction in the vibration velocities of the supports, amounting to 80% of their initial value.

AbstractUsing the most advanced anisotropic (2D) Fokker-Planck (FP) models, we calculate the evolution of the mass functions of the Galactic globular cluster system (GCMF). Our models include two-body relaxation, binary heating, tidal shocks, dynamical friction, stellar evolution, and realistic cluster orbits. We perform 2D-FP simulations for a large number of virtual globular clusters and synthesize these results to study the relation between the initial and present GCMFs. We found two probable IGCMFs that eventually evolve into the Milky Way GCMF : truncated power-law, and log-normal model with higher initial low mass limit and peak mass than the earlier studies.

The prediction of the ablation rate of silicone rubber-based composites is of great significance to accelerate the development of flexible thermal protection materials. Herein, a method which combines uniform design experimentation, active learning, and virtual sample generation was proposed to establish a prediction model of the mass ablation rate based on a small dataset. Briefly, a small number of sample points were collected using uniform design experimentation, which were marked to construct the initial dataset and primitive model. Then, data points were acquired from the sample pool and iterated using various integrated algorithms through active learning to update the above dataset and model. Finally, a large number of virtual samples were generated based on the optimal model, and a further optimized prediction model was achieved. The results showed that after introducing 300 virtual samples, the average percentage error of the gradient boosting decision tree (GBDT) prediction model on the test set decreased to 3.1%, which demonstrates the effectiveness of the proposed method in building prediction models based on a small dataset.

Damage identification methods based on structural modal parameters are influenced by the structure form, number of measuring sensors and noise, resulting in insufficient modal data and low damage identification accuracy. The additional virtual mass method introduced in this study is based on the virtual deformation method for deriving the frequency-domain response equation of the virtual structure and identify its mode to expand the modal information of the original structure. Based on the initial condition assumption that the structural damage was sparse, the damage identification method based on sparsity with l1 and l2 norm of the damage-factor variation and the orthogonal matching pursuit (OMP) method based on the l0 norm were introduced. According to the characteristics of the additional virtual mass method, an improved OMP method (IOMP) was developed to improve the localization of optimal solution determined using the OMP method and the damage substructure selection process, analyze the damage in the entire structure globally, and improve damage identification accuracy. The accuracy and robustness of each damage identification method for multi-damage scenario were analyzed and verified through simulation and experiment.

Based on the vehicle crash finite element theory and the virtual proving ground (VPG), vehicle frontal crash is simulated. Under the VPG environment, the unit element meshes are determined for the entire vehicle CAD model, whereas the element types and material parameters, together with welding nodes, contacts and constraints are defined. According to the ECER94 safety regulations, a rigid wall model, along with initial crash conditions is established. By calling the LS-DYNA, the simulation model is calculated and the stress distribution, vehicle body aberration nephogram, energy and acceleration curves are attained. Afterwards, the vehicle crash safety performance is obtained through simulation. Therefore, this approach sets a reference for vehicle mass assessment.

Aims. We introduce a new model for coronal mass ejections (CMEs) that has been implemented in the magnetohydrodynamics (MHD) inner heliosphere model EUHFORIA. Utilising a linear force-free spheromak (LFFS) solution, the model provides an intrinsic magnetic field structure for the CME. As a result, the new model has the potential to predict the magnetic components of CMEs at Earth. In this paper, we present the implementation of the new model and show the capability of the new model. Methods. We present initial validation runs for the new magnetised CME model by considering the same set of events as used in the initial validation run of EUHFORIA that employed the Cone model. In particular, we have focused on modelling the CME that was responsible for creating the largest geomagnetic disturbance (Dst index). Two scenarios are discussed: one where a single magnetised CME is launched and another in which we launch all five Earth-directed CMEs that were observed during the considered time period. Four out of the five CMEs were modelled using the Cone model. Results. In the first run, where the propagation of a single magnetized CME is considered, we find that the magnetic field components at Earth are well reproduced as compared to in-situ spacecraft data. Considering a virtual spacecraft that is separated approximately seven heliographic degrees from the position of Earth, we note that the centre of the magnetic cloud is missing Earth and a considerably larger magnetic field strength can be found when shifting to that location. For the second run, launching four Cone CMEs and one LFFS CME, we notice that the simulated magnetised CME is arriving at the same time as in the corresponding full Cone model run. We find that to achieve this, the speed of the CME needs to be reduced in order to compensate for the expansion of the CME due to the addition of the magnetic field inside the CME. The reduced initial speed of the CME and the added magnetic field structure give rise to a very similar propagation of the CME with approximately the same arrival time at 1 au. In contrast to the Cone model, however, the magnetised CME is able to predict the magnetic field components at Earth. However, due to the interaction between the Cone model CMEs and the magnetised CME, the magnetic field amplitude is significantly lower than for the run using a single magnetised CME. Conclusions. We have presented the LFFS model that is able to simulate and predict the magnetic field components and the propagation of magnetised CMEs in the inner heliosphere and at Earth. We note that shifting towards a virtual spacecraft in the neighbourhood of Earth can give rise to much stronger magnetic field components. This gives the option of adding a grid of virtual spacecrafts to give a range of values for the magnetic field components.

Abstract Elasticity is one of the materials that students learn through laboratory experiments. In general, real and virtual laboratory conditions are still limited to spring elasticity experiments where the elasticity properties can be observed directly to determine the material’s elastic modulus. While on other objects and materials, elasticity experiments are still problematic to do because of the limitations of measuring instruments and microscopic observation scales. This study aims to produce a virtual laboratory of the Elasticity of various materials using wire for physics learning in universities. This study chose the Development Research (DDR) design with the ADDIE model for its development. The feasibility of the virtual laboratory is seen based on the results of the expert validation test. This research produced a Virtual Laboratory on Elasticity using aluminum, steel, iron, brass, nickel, copper, and tin wire. This virtual laboratory has four variables that can be varied, namely the type of wire material, the mass of the object, the diameter of the wire, and the initial length of the wire. The validation results with expert input show that the Elasticity virtual laboratory is valid and can be used for learning physics in universities.

AbstractTo simulate a glacial lake outburst flood, we employ a comprehensive physically based general two-phase mass flow model (Pudasaini, 2012). This model accounts for a strong interaction between the solid and fluid phases and incorporates buoyancy and other dominant physical aspects of the mass flows such as enhanced non-Newtonian viscous stress, virtual mass force and generalized drag. Our real two-phase mass flow simulation describes explicit evolution of the solid and fluid phases and the debris bulk as a whole, akin to torrential debris flows or debris floods during glacial lake outburst floods (GLOFs). The emptying of a lake following rapid collapse of a restraining dam, the consequent downslope motion of a mixed solid–fluid mass, and the tendency of the mass to form extruding plumes are analyzed in detail for different flow configurations, volumes, conduit geometries and boundary conditions. The solid and fluid phases evolve completely differently and reveal fundamentally different dynamical behaviours. During the flow, the relatively long fluid tail follows the solid-rich dense frontal surge head. The bulk debris develops into a frontal and side levee as derived from the initial frontal moraine dam. Results show that our high-resolution, unified simulation strategies and the advanced model equations can be applied to study the flow dynamics of a wide range of geophysical mass flows such as snow and rock–ice avalanches, debris flows and flash floods as well as GLOFs. This may help substantially in forming a basis for appropriate mitigation measures against potential natural hazards in high mountain slopes and valleys.

The work is devoted to the virtual simulation of a sheet roll working layer formation at a technological stage “casting-solidification”. To form a virtual model of a roller mould pouring and foundry solidification there was used a computer modeling system (CMS) which included initial and boundary conditions for a roller mould pouring process with highalloy cast iron in the field of centrifugal force action. The distribution of a metal working layer along an inner surface of a rotating mould at different technological parameters: mass of highalloy cast iron, its density, temperature and pouring velocity, temperature of metal and non-metal parts of a mould at the initial point of time, modes of rotation and conditions of mould cooling and others were investigated. It is established that under the influence of centrifugal forces a free surface of liquid melt obtains a parabolic form. The influence of basic technological parameters upon the vertex position of a paraboloid of revolution of highalloy liquid melt z0 is revealed. It is shown in the paper that it stipulates for the unevenness of a working layer value along a roller barrel. As a result of computations it is obtained that the value of a working layer at lower flanks of barrels is higher than that of upper sides. The average value of such an exceeding makes 0.012 m. As a result of a simulation analysis of a foundry formation process at different technological parameters it is determined that the distance increase between the vertex of a paraboloid of revolution and the metal area investigated raises the working layer evenness along a roller barrel 3.6 times. Hence, the increase of capacity for work of a rolling tool is expected. The results of investigations presented are basic for the works for the increase of centrifugal roller servicing characteristic increase.

Marrying traditional methods of computer programming with an artistic temperament allows the birth of a new phenomenon: the aesthetic program. The work of the author and his students builds on visual ap-proaches in programming as well as in software modeling, leading toward a gradual evolution from program to model. The need for the aes-thetic model is increased with the importance of personalized, individually tailored media, as found with web-based style sheets and the economic movement termed “mass customization.” The author and his students have formulated the rube Project methodology around the use of 3D web-based virtual-world model construction. Initial results suggest that these models are artistic, while containing symbolism and concise metaphoric mapping sufficient to be executable on a computer.

La pyrolyse du bois est un processus crucial dans la science de la sécurité incendie car elle affecte la décomposition thermique et le comportement de combustion des matériaux. Le bois est un composite biopolymères (cellulose, hémicellulose et lignine) qui subit une pyrolyse complexe, produisant du charbon solide, du goudron et des gaz. Le processus de pyrolyse modifie également certaines caractéristiques importantes de l’échantillon (densité, conductivité thermique, capacité thermique, porosité, perméabilité, émissivité...) qui évoluent tout au long de la réaction de décomposition. La compréhension de ces transformations est cruciale pour la modélisation du comportement du feu des solides. Les évolutions des masses normalisées finales entre les expériences ATG et en cône calorimètre remettent en cause les modèles de taux de réaction solides existants. Les modèles actuels supposent souvent un ordre de réaction égal à 1, ce qui conduit à des inexactitudes lorsque l’ordre de réaction diffère de 1. Pour surmonter ces lacunes, un nouveau modèle basé sur la conversion, appelé ”Masse Initiale Virtuelle”, est proposé. Ce modèle est basé sur des données issues d’essais ATG. Il calcule la vitesse de chaque réaction dans le cas de mécanismes de pyrolyse complexes, avec de nombreuses réactions séquentielles et compétitives et a été implémenté en C++. Le code C++ de ce modèle est intégré avec l’outil DAKOTA pour permettre l’optimisation multi-objectif par algorithme génétique (MOGA) des paramètres cinétiques sur plusieurs vitesses de chauffage. Ce modèle de « Masse Initiale Virtuelle » est intégré dans la boîte à outils d’analyse des matériaux poreux basée sur OpenFOAM (PATO), un outil Open Source créé par la NASA. D’autres modèles de transferts de masse, de chaleur et de conservation des espèces en plus des propriétés des matériaux sont créés dans ce nouveau cadre. Un modèle informatique pour les réactions secondaires (réactions en phase gazeuse qui produisent du charbon secondaire) est implémenté dans PATO. Les simulations des essais en cône calorimètre sont effectuées dans des modèles 1D et 2D axisymétriques pour explorer l’influence des propriétés anisotropes du bois, en particulier l’orientation de ses fibres. La comparaison des modèles avec et sans réactions secondaires démontre le rôle de ces dernières dans la distribution de la chaleur et la production de charbon secondaire. Ce résultat explique la différence de masse finale observée expérimentalement entre les tests en ATG et en cône calorimètre. La comparaison des résultats expérimentaux et numériques montre la pertinence de cette approche pour simuler le comportement complexe de la pyrolyse du bois en mettant en évidence l’importance des voies de réaction, des réactions secondaires, du transfert de chaleur, du transfert de masse et des phénomènes d’interaction intra-pore
Pyrolysis of wood is a crucial process in fire safety science because it affects the thermal decomposition and combustion behavior of materials. Wood, a composite of biopolymeric components (cellulose, hemicellulose and lignin) undergoes complex pyrolysis to yield solid char, tar and gases as it thermally decomposes. The pyrolysis process also changes some important characteristics of the sample (density, thermal conductivity, heat capacity, porosity, permeability, emissivity...) that evolve throughout the reaction. Understanding these transformations is crucial for the correct modeling of fire behavior and material response under different thermal conditions. Different final normalized mass between TGA and cone calorimeter experiments challenge existing solid reaction rate models, according to experimental studies. Current models often assume a reaction order of 1, which oversimplifies the complexity of wood pyrolysis and leads to inaccuracies when the reaction order differs from 1. To overcome these shortcomings, a brand new conversion-based model, called ”Virtual Initial Mass”, is proposed. This model, based on TGA data, calculates the reaction rate for each reaction in complicated pyrolysis mechanisms. It supports mechanisms with numerous sequential and competitive reactions and has been implemented in C++. The C++ code for this model is integrated with the DAKOTA toolkit to perform multi objective genetic algorithm (MOGA) optimization of kinetic parameters for multiple heating rates. This ”Virtual Initial Mass” model is integrated in the Porous material Analysis Toolbox based on OpenFOAM (PATO) an Open Source tool distributed by NASA. Further mass transfer, heat transfer, species conservation models in addition to material properties are created within this new framework. A computational model for secondary reactions (gas-phase reactions that produce secondary char) is implemented in PATO. These secondary reactions solidify the sample and distribute heat back into the system. Simulations of cone calorimeter tests are performed in 1D and 2D axisymmetric models to explore the influence of anisotropic wood properties, particularly the orientation of wood fibers. Comparison of models with and without secondary reactions demonstrates their role in heat distribution and secondary char production and points out the experimentally observed difference in normalized mass between TGA and cone calorimeter tests. The model is verified by comparison with experimental results to show that it can simulate the complicated behavior of wood pyrolysis as well as emphasizes the importance of reaction pathways, secondary reactions, heat transfer, mass transfer and intra-pore interaction phenomena

AIMS: We develop a new theoretical framework to generate Besançon Galaxy Model Fast Approximate Simulations (BGM FASt) to address fundamental questions of the Galactic structure and evolution performing multi-parameter inference. The flexibility of BGM FASt allows the inference of fundamental parameters related to the stellar initial mass function (IMF), the star formation history (SFH), the density distribution, the kinematics and the chemo-dynamics, among others. BGM FASt allows the study of different Milky Way (MW) components. In this thesis we are focused in a first application of our strategy to simultaneously infer the IMF and the SFH of the MW disc. METHOD: BGM FASt is based on a reweighing scheme, that uses a specific pre-sampled simulation. We use BGM FASt together with an approximate Bayesian computation algorithm to obtain the posterior probability distribution function of the inferred parameters, by automatically comparing synthetic versus observed data. Our full strategy is codified to run on Apache Spark and Hadoop, suited to deal with large surveys. BGM FASt is implemented in the big data infrastructure known as Gaia Data Analytics Framework (GDAF) at the University of Barcelona. To evaluate the performance of BGM FASt we execute a set of validation tests comparing density, colour, mass and age distributions of BGM FASt versus BGM standard simulations. We present two scientific cases that compare synthetic versus Tycho-2 colour-magnitude diagrams. We obtain for the first time using BGM an IMF and SFH of the thin disc by exploring a 6-Dimensional parameter space. We use Gaia data-release 2 magnitudes, colours, and parallaxes for stars with G<12 to explore a parameter space with 15 dimensions. This includes simultaneously the IMF and, for the first time, a non-parametric SFH for the Galactic disc. RESULTS: The set of tests applied show a very good agreement between equivalent simulations performed with BGM FASt and standard BGM. It has resulted to be 10000 times faster. We demonstrate it is a very valuable tool to perform multi-parameter inference using large catalogues. The two scientific demonstration cases of our strategy applied to Tyhco-2 data gives us, for the first time using BGM, a full 6D posterior probability distribution function of the parameters involved in the IMF and the SFH of the thin disc component. Using Gaia DR2 we find an imprint of a star formation burst 2-3 Gyr ago in the Galactic thin disc domain. Our results show a decreasing trend followed by a Star Formation Rate (SFR) enhancement starting at about 5 Gyr ago and continuing until about 1 Gyr ago. This enhancement is detected with high statistical significance by discarding the null hypothesis of an exponential SFH. The timescale and the amount of stellar mass generated during this SFR enhancement event lead us to hypothesise that its origin, currently under investigation, is not intrinsic to the disc. When we adopt a non-parametric SFH the resulting IMF for the thin disc has an alpha3 of approximately 2 for masses M larger than 1.53 Msun and alpha2 approximately 1.3 for the mass range between 0.5 and 1.53Msun. CONCLUSIONS: BGM FASt has allowed us to increase our knowledge about the IMF and the SFH of the MW disc. Our results have shown that the evolution of the SFR with time is much more complex than a simple mathematical exponential decreasing shape. We have seen how the imposition of a mathematical shape for the SFH has a clear impact into the derivation of the IMF at high masses. The good performance of our whole strategy opens very promising perspectives, among them, the possibility to study whether the IMF variates with the time or not.

Савушкіна К. К. Теоретико-методичні засади впровадження змішаного навчання в освітній процес закладу вищої освіти : кваліфікаційна робота магістра спеціальності 011 «Освітні, педагогічні науки» / наук. керівник О. І. Гура. Запоріжжя : ЗНУ, 2020. 94 с.
UA : Робота викладена на 94 сторінках друкованого тексту. Перелік посилань включає 82 джерела, з них на іноземній мові – 24. Об’єкт дослідження: організація освітнього процесу закладу вищої освіти. Предмет дослідження: теоретико-методичні аспекти впровадження змішаного навчання в освітній процес закладу вищої освіти на прикладі моделі «перевернутий клас». Мета дослідження: теоретично обґрунтувати доцільність впровадження змішаного навчання в освітній процес закладу вищої освіти та надати методичні рекомендації стосовно організації навчального процесу на прикладі моделі «перевернутий клас». В роботі розкрито науково-теоретичні основи розуміння сутності змішаного навчання у вітчизняних та зарубіжних наукових працях; визначено й охарактеризовано напрямки реалізації змішаного навчання у вітчизняній системі освіти; здійснено аналіз моделей змішаного навчання, надавши їх загальну характеристику; надано методичні рекомендації стосовно організації навчального процесу у закладі вищої освіти на прикладі моделі «перевернутий клас». Практичне значення роботи полягає у наданні методичних рекомендацій стосовно організації навчального процесу на засадах змішаного навчання на прикладі моделі «перевернутий клас».
EN : The work is presented on 94 pages of printed text. The list of references includes 82 sources, 24 of them in foreign language. The object of the study: organization of the educational process of a higher education institution. Subject of research: theoretical and methodological aspects of the introduction of blended learning in the educational process of higher education institutions on the example of the model "inverted class". The purpose of the study: to theoretically justify the feasibility of introducing blended learning in the educational process of higher education and provide guidelines for the organization of the educational process on the example of the model "inverted classroom". The paper reveals the scientific and theoretical foundations of understanding the essence of blended learning in domestic and foreign scientific works; the directions of realization of blended learning in the domestic system of education are defined and characterized; the analysis of models of blended learning is carried out, giving their general characteristic; methodical recommendations concerning the organization of educational process in an institution of higher education on the example of the model "inverted class" are given. The practical significance of the work is to provide guidelines for the organization of the educational process on the basis of blended learning on the example of the model "inverted classroom".

The aim of the paper was to determine the influence of root systems of chosen tree species found in the Polish Flysch Carpathians on the increase of soil shear strength (root cohesion) in terms of slope stability. The paper's goal was achieved through comprehensive tests on root systems of eight relatively common in the Polish Flysch Carpathians tree species. The tests that were carried out included field work, laboratory work and analytical calculations. As part of the field work, the root area ratio (A IA) of the roots was determined using the method of profiling the walls of the trench at a distance of about 1.0 m from the tree trunk. The width of the. trenches was about 1.0 m, and their depth depended on the ground conditions and ranged from 0.6 to 1.0 m below the ground level. After preparing the walls of the trench, the profile was divided into vertical layers with a height of 0.1 m, within which root diameters were measured. Roots with diameters from 1 to 10 mm were taken into consideration in root area ratio calculations in accordance with the generally accepted methodology for this type of tests. These measurements were made in Biegnik (silver fir), Ropica Polska (silver birch, black locust) and Szymbark (silver birch, European beech, European hornbeam, silver fir, sycamore maple, Scots pine, European spruce) located near Gorlice (The Low Beskids) in areas with unplanned forest management. In case of each tested tree species the samples of roots were taken, transported to the laboratory and then saturated with water for at least one day. Before testing the samples were obtained from the water and stretched in a. tensile testing machine in order to determine their tensile strength and flexibility. In general, over 2200 root samples were tested. The results of tests on root area ratio of root systems and their tensile strength were used to determine the value of increase in shear strength of the soils, called root cohesion. To this purpose a classic Wu-Waldron calculation model was used as well as two types of bundle models, the so called static model (Fiber Bundle Model — FIRM, FBM2, FBM3) and the deformation model (Root Bundle Model— RBM1, RBM2, mRBM1) that differ in terms of the assumptions concerning the way the tensile force is distributed to the roots as well as the range of parameters taken into account during calculations. The stability analysis of 8 landslides in forest areas of Cicikowicleie and Wignickie Foothills was a form of verification of relevance of the obtained calculation results. The results of tests on root area ratio in the profile showed that, as expected, the number of roots in the soil profile and their ApIA values are very variable. It was shown that the values of the root area ratio of the tested tree species with a diameter 1-10 ram are a maximum of 0.8% close to the surface of the ground and they decrease along with the depth reaching the values at least one order of magnitude lower than close to the surface at the depth 0.5-1.0 m below the ground level. Average values of the root area ratio within the soil profile were from 0.05 to 0.13% adequately for Scots pine and European beech. The measured values of the root area ratio are relatively low in relation to the values of this parameter given in literature, which is probably connected with great cohesiveness of the soils and the fact that there were a lot of rock fragments in the soil, where the tests were carried out. Calculation results of the Gale-Grigal function indicate that a distribution of roots in the soil profile is similar for the tested species, apart from the silver fir from Bie§nik and European hornbeam. Considering the number of roots, their distribution in the soil profile and the root area ratio it appears that — considering slope stability — the root systems of European beech and black locust are the most optimal, which coincides with tests results given in literature. The results of tensile strength tests showed that the roots of the tested tree species have different tensile strength. The roots of European beech and European hornbeam had high tensile strength, whereas the roots of conifers and silver birch in deciduous trees — low. The analysis of test results also showed that the roots of the studied tree species are characterized by high variability of mechanical properties. The values Of shear strength increase are mainly related to the number and size (diameter) of the roots in the soil profile as well as their tensile strength and pullout resistance, although they can also result from the used calculation method (calculation model). The tests showed that the distribution of roots in the soil and their tensile strength are characterized by large variability, which allows the conclusion that using typical geotechnical calculations, which take into consideration the role of root systems is exposed to a high risk of overestimating their influence on the soil reinforcement. hence, while determining or assuming the increase in shear strength of soil reinforced with roots (root cohesion) for design calculations, a conservative (careful) approach that includes the most unfavourable values of this parameter should be used. Tests showed that the values of shear strength increase of the soil reinforced with roots calculated using Wu-Waldron model in extreme cases are three times higher than the values calculated using bundle models. In general, the most conservative calculation results of the shear strength increase were obtained using deformation bundle models: RBM2 (RBMw) or mRBM1. RBM2 model considers the variability of strength characteristics of soils described by Weibull survival function and in most cases gives the lowest values of the shear strength increase, which usually constitute 50% of the values of shear strength increase determined using classic Wu-Waldron model. Whereas the second model (mRBM1.) considers averaged values of roots strength parameters as well as the possibility that two main mechanism of destruction of a root bundle - rupture and pulling out - can occur at the same. time. The values of shear strength increase calculated using this model were the lowest in case of beech and hornbeam roots, which had high tensile strength. It indicates that in the surface part of the profile (down to 0.2 m below the ground level), primarily in case of deciduous trees, the main mechanism of failure of the root bundle will be pulling out. However, this model requires the knowledge of a much greater number of geometrical parameters of roots and geotechnical parameters of soil, and additionally it is very sensitive to input data. Therefore, it seems practical to use the RBM2 model to assess the influence of roots on the soil shear strength increase, and in order to obtain safe results of calculations in the surface part of the profile, the Weibull shape coefficient equal to 1.0 can be assumed. On the other hand, the Wu-Waldron model can be used for the initial assessment of the shear strength increase of soil reinforced with roots in the situation, where the deformation properties of the root system and its interaction with the soil are not considered, although the values of the shear strength increase calculated using this model should be corrected and reduced by half. Test results indicate that in terms of slope stability the root systems of beech and hornbeam have the most favourable properties - their maximum effect of soil reinforcement in the profile to the depth of 0.5 m does not usually exceed 30 kPa, and to the depth of 1 m - 20 kPa. The root systems of conifers have the least impact on the slope reinforcement, usually increasing the soil shear strength by less than 5 kPa. These values coincide to a large extent with the range of shear strength increase obtained from the direct shear test as well as results of stability analysis given in literature and carried out as part of this work. The analysis of the literature indicates that the methods of measuring tree's root systems as well as their interpretation are very different, which often limits the possibilities of comparing test results. This indicates the need to systematize this type of tests and for this purpose a root distribution model (RDM) can be used, which can be integrated with any deformation bundle model (RBM). A combination of these two calculation models allows the range of soil reinforcement around trees to be determined and this information might be used in practice, while planning bioengineering procedures in areas exposed to surface mass movements. The functionality of this solution can be increased by considering the dynamics of plant develop¬ment in the calculations. This, however, requires conducting this type of research in order to obtain more data.

Nationalism: Past as Prologue began as a single volume being compiled by Ad Akande, a scholar from South Africa, who proposed it to me as co-author about two years ago. The original idea was to examine how the damaging roots of nationalism have been corroding political systems around the world, and creating dangerous obstacles for necessary international cooperation. Since I (Bruce E. Johansen) has written profusely about climate change (global warming, a.k.a. infrared forcing), I suggested a concerted effort in that direction. This is a worldwide existential threat that affects every living thing on Earth. It often compounds upon itself, so delays in reducing emissions of fossil fuels are shortening the amount of time remaining to eliminate the use of fossil fuels to preserve a livable planet. Nationalism often impedes solutions to this problem (among many others), as nations place their singular needs above the common good. Our initial proposal got around, and abstracts on many subjects arrived. Within a few weeks, we had enough good material for a 100,000-word book. The book then fattened to two moderate volumes and then to four two very hefty tomes. We tried several different titles as good submissions swelled. We also discovered that our best contributors were experts in their fields, which ranged the world. We settled on three stand-alone books:” 1/ nationalism and racial justice. Our first volume grew as the growth of Black Lives Matter following the brutal killing of George Floyd ignited protests over police brutality and other issues during 2020, following the police assassination of Floyd in Minneapolis. It is estimated that more people took part in protests of police brutality during the summer of 2020 than any other series of marches in United States history. This includes upheavals during the 1960s over racial issues and against the war in Southeast Asia (notably Vietnam). We choose a volume on racism because it is one of nationalism’s main motive forces. This volume provides a worldwide array of work on nationalism’s growth in various countries, usually by authors residing in them, or in the United States with ethnic ties to the nation being examined, often recent immigrants to the United States from them. Our roster of contributors comprises a small United Nations of insightful, well-written research and commentary from Indonesia, New Zealand, Australia, China, India, South Africa, France, Portugal, Estonia, Hungary, Russia, Poland, Kazakhstan, Georgia, and the United States. Volume 2 (this one) describes and analyzes nationalism, by country, around the world, except for the United States; and 3/material directly related to President Donald Trump, and the United States. The first volume is under consideration at the Texas A & M University Press. The other two are under contract to Nova Science Publishers (which includes social sciences). These three volumes may be used individually or as a set. Environmental material is taken up in appropriate places in each of the three books. * * * * * What became the United States of America has been strongly nationalist since the English of present-day Massachusetts and Jamestown first hit North America’s eastern shores. The country propelled itself across North America with the self-serving ideology of “manifest destiny” for four centuries before Donald Trump came along. Anyone who believes that a Trumpian affection for deportation of “illegals” is a new thing ought to take a look at immigration and deportation statistics in Adam Goodman’s The Deportation Machine: America’s Long History of Deporting Immigrants (Princeton University Press, 2020). Between 1920 and 2018, the United States deported 56.3 million people, compared with 51.7 million who were granted legal immigration status during the same dates. Nearly nine of ten deportees were Mexican (Nolan, 2020, 83). This kind of nationalism, has become an assassin of democracy as well as an impediment to solving global problems. Paul Krugman wrote in the New York Times (2019:A-25): that “In their 2018 book, How Democracies Die, the political scientists Steven Levitsky and Daniel Ziblatt documented how this process has played out in many countries, from Vladimir Putin’s Russia, to Recep Erdogan’s Turkey, to Viktor Orban’s Hungary. Add to these India’s Narendra Modi, China’s Xi Jinping, and the United States’ Donald Trump, among others. Bit by bit, the guardrails of democracy have been torn down, as institutions meant to serve the public became tools of ruling parties and self-serving ideologies, weaponized to punish and intimidate opposition parties’ opponents. On paper, these countries are still democracies; in practice, they have become one-party regimes….And it’s happening here [the United States] as we speak. If you are not worried about the future of American democracy, you aren’t paying attention” (Krugmam, 2019, A-25). We are reminded continuously that the late Carl Sagan, one of our most insightful scientific public intellectuals, had an interesting theory about highly developed civilizations. Given the number of stars and planets that must exist in the vast reaches of the universe, he said, there must be other highly developed and organized forms of life. Distance may keep us from making physical contact, but Sagan said that another reason we may never be on speaking terms with another intelligent race is (judging from our own example) could be their penchant for destroying themselves in relatively short order after reaching technological complexity. This book’s chapters, introduction, and conclusion examine the worldwide rise of partisan nationalism and the damage it has wrought on the worldwide pursuit of solutions for issues requiring worldwide scope, such scientific co-operation public health and others, mixing analysis of both. We use both historical description and analysis. This analysis concludes with a description of why we must avoid the isolating nature of nationalism that isolates people and encourages separation if we are to deal with issues of world-wide concern, and to maintain a sustainable, survivable Earth, placing the dominant political movement of our time against the Earth’s existential crises. Our contributors, all experts in their fields, each have assumed responsibility for a country, or two if they are related. This work entwines themes of worldwide concern with the political growth of nationalism because leaders with such a worldview are disinclined to co-operate internationally at a time when nations must find ways to solve common problems, such as the climate crisis. Inability to cooperate at this stage may doom everyone, eventually, to an overheated, stormy future plagued by droughts and deluges portending shortages of food and other essential commodities, meanwhile destroying large coastal urban areas because of rising sea levels. Future historians may look back at our time and wonder why as well as how our world succumbed to isolating nationalism at a time when time was so short for cooperative intervention which is crucial for survival of a sustainable earth. Pride in language and culture is salubrious to individuals’ sense of history and identity. Excess nationalism that prevents international co-operation on harmful worldwide maladies is quite another. As Pope Francis has pointed out: For all of our connectivity due to expansion of social media, ability to communicate can breed contempt as well as mutual trust. “For all our hyper-connectivity,” said Francis, “We witnessed a fragmentation that made it more difficult to resolve problems that affect us all” (Horowitz, 2020, A-12). The pope’s encyclical, titled “Brothers All,” also said: “The forces of myopic, extremist, resentful, and aggressive nationalism are on the rise.” The pope’s document also advocates support for migrants, as well as resistance to nationalist and tribal populism. Francis broadened his critique to the role of market capitalism, as well as nationalism has failed the peoples of the world when they need co-operation and solidarity in the face of the world-wide corona virus pandemic. Humankind needs to unite into “a new sense of the human family [Fratelli Tutti, “Brothers All”], that rejects war at all costs” (Pope, 2020, 6-A). Our journey takes us first to Russia, with the able eye and honed expertise of Richard D. Anderson, Jr. who teaches as UCLA and publishes on the subject of his chapter: “Putin, Russian identity, and Russia’s conduct at home and abroad.” Readers should find Dr. Anderson’s analysis fascinating because Vladimir Putin, the singular leader of Russian foreign and domestic policy these days (and perhaps for the rest of his life, given how malleable Russia’s Constitution has become) may be a short man physically, but has high ambitions. One of these involves restoring the old Russian (and Soviet) empire, which would involve re-subjugating a number of nations that broke off as the old order dissolved about 30 years ago. President (shall we say czar?) Putin also has international ambitions, notably by destabilizing the United States, where election meddling has become a specialty. The sight of Putin and U.S. president Donald Trump, two very rich men (Putin $70-$200 billion; Trump $2.5 billion), nuzzling in friendship would probably set Thomas Jefferson and Vladimir Lenin spinning in their graves. The road of history can take some unanticipated twists and turns. Consider Poland, from which we have an expert native analysis in chapter 2, Bartosz Hlebowicz, who is a Polish anthropologist and journalist. His piece is titled “Lawless and Unjust: How to Quickly Make Your Own Country a Puppet State Run by a Group of Hoodlums – the Hopeless Case of Poland (2015–2020).” When I visited Poland to teach and lecture twice between 2006 and 2008, most people seemed to be walking on air induced by freedom to conduct their own affairs to an unusual degree for a state usually squeezed between nationalists in Germany and Russia. What did the Poles then do in a couple of decades? Read Hlebowicz’ chapter and decide. It certainly isn’t soft-bellied liberalism. In Chapter 3, with Bruce E. Johansen, we visit China’s western provinces, the lands of Tibet as well as the Uighurs and other Muslims in the Xinjiang region, who would most assuredly resent being characterized as being possessed by the Chinese of the Han to the east. As a student of Native American history, I had never before thought of the Tibetans and Uighurs as Native peoples struggling against the Independence-minded peoples of a land that is called an adjunct of China on most of our maps. The random act of sitting next to a young woman on an Air India flight out of Hyderabad, bound for New Delhi taught me that the Tibetans had something to share with the Lakota, the Iroquois, and hundreds of other Native American states and nations in North America. Active resistance to Chinese rule lasted into the mid-nineteenth century, and continues today in a subversive manner, even in song, as I learned in 2018 when I acted as a foreign adjudicator on a Ph.D. dissertation by a Tibetan student at the University of Madras (in what is now in a city called Chennai), in southwestern India on resistance in song during Tibet’s recent history. Tibet is one of very few places on Earth where a young dissident can get shot to death for singing a song that troubles China’s Quest for Lebensraum. The situation in Xinjiang region, where close to a million Muslims have been interned in “reeducation” camps surrounded with brick walls and barbed wire. They sing, too. Come with us and hear the music. Back to Europe now, in Chapter 4, to Portugal and Spain, we find a break in the general pattern of nationalism. Portugal has been more progressive governmentally than most. Spain varies from a liberal majority to military coups, a pattern which has been exported to Latin America. A situation such as this can make use of the term “populism” problematic, because general usage in our time usually ties the word into a right-wing connotative straightjacket. “Populism” can be used to describe progressive (left-wing) insurgencies as well. José Pinto, who is native to Portugal and also researches and writes in Spanish as well as English, in “Populism in Portugal and Spain: a Real Neighbourhood?” provides insight into these historical paradoxes. Hungary shares some historical inclinations with Poland (above). Both emerged from Soviet dominance in an air of developing freedom and multicultural diversity after the Berlin Wall fell and the Soviet Union collapsed. Then, gradually at first, right wing-forces began to tighten up, stripping structures supporting popular freedom, from the courts, mass media, and other institutions. In Chapter 5, Bernard Tamas, in “From Youth Movement to Right-Liberal Wing Authoritarianism: The Rise of Fidesz and the Decline of Hungarian Democracy” puts the renewed growth of political and social repression into a context of worldwide nationalism. Tamas, an associate professor of political science at Valdosta State University, has been a postdoctoral fellow at Harvard University and a Fulbright scholar at the Central European University in Budapest, Hungary. His books include From Dissident to Party Politics: The Struggle for Democracy in Post-Communist Hungary (2007). Bear in mind that not everyone shares Orbán’s vision of what will make this nation great, again. On graffiti-covered walls in Budapest, Runes (traditional Hungarian script) has been found that read “Orbán is a motherfucker” (Mikanowski, 2019, 58). Also in Europe, in Chapter 6, Professor Ronan Le Coadic, of the University of Rennes, Rennes, France, in “Is There a Revival of French Nationalism?” Stating this title in the form of a question is quite appropriate because France’s nationalistic shift has built and ebbed several times during the last few decades. For a time after 2000, it came close to assuming the role of a substantial minority, only to ebb after that. In 2017, the candidate of the National Front reached the second round of the French presidential election. This was the second time this nationalist party reached the second round of the presidential election in the history of the Fifth Republic. In 2002, however, Jean-Marie Le Pen had only obtained 17.79% of the votes, while fifteen years later his daughter, Marine Le Pen, almost doubled her father's record, reaching 33.90% of the votes cast. Moreover, in the 2019 European elections, re-named Rassemblement National obtained the largest number of votes of all French political formations and can therefore boast of being "the leading party in France.” The brutality of oppressive nationalism may be expressed in personal relationships, such as child abuse. While Indonesia and Aotearoa [the Maoris’ name for New Zealand] hold very different ranks in the United Nations Human Development Programme assessments, where Indonesia is classified as a medium development country and Aotearoa New Zealand as a very high development country. In Chapter 7, “Domestic Violence Against Women in Indonesia and Aotearoa New Zealand: Making Sense of Differences and Similarities” co-authors, in Chapter 8, Mandy Morgan and Dr. Elli N. Hayati, from New Zealand and Indonesia respectively, found that despite their socio-economic differences, one in three women in each country experience physical or sexual intimate partner violence over their lifetime. In this chapter ther authors aim to deepen understandings of domestic violence through discussion of the socio-economic and demographic characteristics of theit countries to address domestic violence alongside studies of women’s attitudes to gender norms and experiences of intimate partner violence. One of the most surprising and upsetting scholarly journeys that a North American student may take involves Adolf Hitler’s comments on oppression of American Indians and Blacks as he imagined the construction of the Nazi state, a genesis of nationalism that is all but unknown in the United States of America, traced in this volume (Chapter 8) by co-editor Johansen. Beginning in Mein Kampf, during the 1920s, Hitler explicitly used the westward expansion of the United States across North America as a model and justification for Nazi conquest and anticipated colonization by Germans of what the Nazis called the “wild East” – the Slavic nations of Poland, the Baltic states, Ukraine, and Russia, most of which were under control of the Soviet Union. The Volga River (in Russia) was styled by Hitler as the Germans’ Mississippi, and covered wagons were readied for the German “manifest destiny” of imprisoning, eradicating, and replacing peoples the Nazis deemed inferior, all with direct references to events in North America during the previous century. At the same time, with no sense of contradiction, the Nazis partook of a long-standing German romanticism of Native Americans. One of Goebbels’ less propitious schemes was to confer honorary Aryan status on Native American tribes, in the hope that they would rise up against their oppressors. U.S. racial attitudes were “evidence [to the Nazis] that America was evolving in the right direction, despite its specious rhetoric about equality.” Ming Xie, originally from Beijing, in the People’s Republic of China, in Chapter 9, “News Coverage and Public Perceptions of the Social Credit System in China,” writes that The State Council of China in 2014 announced “that a nationwide social credit system would be established” in China. “Under this system, individuals, private companies, social organizations, and governmental agencies are assigned a score which will be calculated based on their trustworthiness and daily actions such as transaction history, professional conduct, obedience to law, corruption, tax evasion, and academic plagiarism.” The “nationalism” in this case is that of the state over the individual. China has 1.4 billion people; this system takes their measure for the purpose of state control. Once fully operational, control will be more subtle. People who are subject to it, through modern technology (most often smart phones) will prompt many people to self-censor. Orwell, modernized, might write: “Your smart phone is watching you.” Ming Xie holds two Ph.Ds, one in Public Administration from University of Nebraska at Omaha and another in Cultural Anthropology from the Chinese Academy of Social Sciences, Beijing, where she also worked for more than 10 years at a national think tank in the same institution. While there she summarized news from non-Chinese sources for senior members of the Chinese Communist Party. Ming is presently an assistant professor at the Department of Political Science and Criminal Justice, West Texas A&M University. In Chapter 10, analyzing native peoples and nationhood, Barbara Alice Mann, Professor of Honours at the University of Toledo, in “Divide, et Impera: The Self-Genocide Game” details ways in which European-American invaders deprive the conquered of their sense of nationhood as part of a subjugation system that amounts to genocide, rubbing out their languages and cultures -- and ultimately forcing the native peoples to assimilate on their own, for survival in a culture that is foreign to them. Mann is one of Native American Studies’ most acute critics of conquests’ contradictions, and an author who retrieves Native history with a powerful sense of voice and purpose, having authored roughly a dozen books and numerous book chapters, among many other works, who has traveled around the world lecturing and publishing on many subjects. Nalanda Roy and S. Mae Pedron in Chapter 11, “Understanding the Face of Humanity: The Rohingya Genocide.” describe one of the largest forced migrations in the history of the human race, the removal of 700,000 to 800,000 Muslims from Buddhist Myanmar to Bangladesh, which itself is already one of the most crowded and impoverished nations on Earth. With about 150 million people packed into an area the size of Nebraska and Iowa (population less than a tenth that of Bangladesh, a country that is losing land steadily to rising sea levels and erosion of the Ganges river delta. The Rohingyas’ refugee camp has been squeezed onto a gigantic, eroding, muddy slope that contains nearly no vegetation. However, Bangladesh is majority Muslim, so while the Rohingya may starve, they won’t be shot to death by marauding armies. Both authors of this exquisite (and excruciating) account teach at Georgia Southern University in Savannah, Georgia, Roy as an associate professor of International Studies and Asian politics, and Pedron as a graduate student; Roy originally hails from very eastern India, close to both Myanmar and Bangladesh, so he has special insight into the context of one of the most brutal genocides of our time, or any other. This is our case describing the problems that nationalism has and will pose for the sustainability of the Earth as our little blue-and-green orb becomes more crowded over time. The old ways, in which national arguments often end in devastating wars, are obsolete, given that the Earth and all the people, plants, and other animals that it sustains are faced with the existential threat of a climate crisis that within two centuries, more or less, will flood large parts of coastal cities, and endanger many species of plants and animals. To survive, we must listen to the Earth, and observe her travails, because they are increasingly our own.

AbstractTwo chassis components were developed at the Technische Universität Darmstadt that are used to isolate the body and to reduce wheel load fluctuation.The frequency responses of the components were identified with a stochastic foot point excitation in a hardware-in-the-loop (HiL) simulation environment at the hydropulser. The modelling of the transmission behaviour influence of the testing machine on the frequency response was approximately represented with a time delay of $$10\,\mathrm {ms}$$ 10 ms in the frequency range up to $$25\,\mathrm {Hz}$$ 25 Hz . This is considered by a Padé approximation. It can be seen that the dynamics of the testing machine have an influence on the wheel load fluctuation and the body acceleration, especially in the natural frequency of the unsprung mass. Therefor, the HiL stability is analysed by mapping the poles of the system in the complex plane, influenced by the time delay and virtual damping.This paper presents the transfer from virtual to real quarter car to quantify the model uncertainty of the component, since the time delay impact does not occur in the real quarter car test rig. The base point excitation directly is provided by the testing machine and not like in the case of the HiL test rig, the compression of the spring damper calculated in the real-time simulation.

AbstractTraditional anti-anonymity technologies for Bitcoin transactions include two types. One is network-layer anti-anonymity technology, which achieves the purpose of locating the initial IP of specific transaction information by speculating on the IP propagation path of transaction; the other is the anti-anonymity technology of the transaction layer. By analyzing the data of the Bitcoin ledger, it realizes the on-chain behavior portrait of a specific wallet address attributable to the user. In this work, we propose a new anti-anonymity technology, by constructing transaction behavior vectors and social behavior vectors based on Bitcoin ledger data and off-chain social data respectively, and build a model for mapping and aligning the two vectors. Experimental test shows that the proposed anti-anonymity technology is more accurate and has better practical effects. Furthermore, the technology suits for the anti-anonymity of other virtual currencies as well.

Fall from height (FFH) is one of the major causes of injury and fatalities in construction industry. Deep learning-based computer vision for safety monitoring has gained attention due to its relatively lower initial cost compared to traditional sensing technologies. However, a single detection model that has been used in many related studies cannot consider various contexts at the construction site. In this paper, we propose a deep learning-based pose estimation approach for identifying potential fall hazards of construction workers. This approach can relatively increase the accuracy of estimating the distance between the worker and the fall hazard area compared to the existing methods from the experimental results. Our proposed approach can improve the robustness of worker location estimation compared to existing methods in complex construction site environments with obstacles that can obstruct the worker's position. Also, it is possible to provide information on whether a worker is aware of a potential fall risk area. Our approach can contribute to preventing FFH by providing access information to fall risk areas such as construction site openings and inducing workers to recognize the risk area even in Inattentional blindness (IB) situations

Fall from height (FFH) is one of the major causes of injury and fatalities in construction industry. Deep learning-based computer vision for safety monitoring has gained attention due to its relatively lower initial cost compared to traditional sensing technologies. However, a single detection model that has been used in many related studies cannot consider various contexts at the construction site. In this paper, we propose a deep learning-based pose estimation approach for identifying potential fall hazards of construction workers. This approach can relatively increase the accuracy of estimating the distance between the worker and the fall hazard area compared to the existing methods from the experimental results. Our proposed approach can improve the robustness of worker location estimation compared to existing methods in complex construction site environments with obstacles that can obstruct the worker's position. Also, it is possible to provide information on whether a worker is aware of a potential fall risk area. Our approach can contribute to preventing FFH by providing access information to fall risk areas such as construction site openings and inducing workers to recognize the risk area even in Inattentional blindness (IB) situations

AbstractThe design optimization of the jacket substructure could reduce the cost of energy and the correlated carbon cost. The mass of jacket is optimized with respect to maximum stress and displacement responses. Wind and dead loads were applied at the top of the jacket referenced point. Wave load and foundation boundary were applied using Dload and UEL function in the Abaqus subroutine. Six different parameters were evaluated, including the pile height above mudline, the base width, brace thickness and diameter, and the main leg thickness and diameter. The parametrically optimized model has mass minimized by 16%. The maximum stress at the top of the optimal jacket reduced to 274.91 MPa from 288.70 MPa. The maximum displacement at the top increased to 87.37 mm from 83.88 mm, albeit, lower than the code limit of 175 mm. The absolute value of the maximum rotation at the top reduced from 0.309° to 0.304°, which is lower than the code limit of 0.382°. The pile rotation at the mudline increased by 14%, from 0.120° to 0.137°, nonetheless, lower than the DNV code limit of 0.250°. Initial numerical basis has been developed for the parametric design optimization of the jacket substructure. From the parameter studies conducted mathematical models could be developed for efficient numerical optimization.

AbstractIn order to further reveal the pile-soil interaction mechanism during precast pile driving in saturated soft soil in coastal areas, the compaction effect and excess pore pressure response of a single pile and adjacent pile penetration under hammer driven pile construction are analyzed by using the cavity expansion and model test method. The results show that pile driving in saturated soil layer will cause large soil compaction and accumulation of excess pore water pressure. Under the model test conditions, the variation range of soil pressure and excess pore pressure is about 0.7–3.0 times and 0.5–1.5 times of soil mass weight stress. As the driving of adjacent pile, soil pressure at the constructed pile-soil interface increases gradually and fluctuates at the same time, and multi peak phenomenon appears under the influence of different soil layers. At the initial stage of driving, the pile driving force is mainly borne by the pile side friction, and the pile tip resistance will actions as the increase of penetration depth, and the relationship between them is basically linear. These results have certain guiding and reference value for the construction of precast pile driving in saturated soft soil in coastal areas.

AbstractA RELAP5 input model was established for a scaled-up facility simulating China's Advanced Passive Water Reactor with passive safety features. The simulation was performed to reproduce a Main Steam Line Break (MSLB) scenario at steam line connected to one Steam Generator. The figure of merit selected in this accident scenario includes the maximum containment pressure, mass and energy release to containment. Driving factors of this response function include Passive Residue Heat Removal material thermal conductivity, Pressurizer temperature, and broken steam line temperature.To achieve an adequately justified safety margin using a Best Estimate Plus Uncertainty analysis, dominant phenomena were selected from a reference Phenomenon Identification and Ranking Table. The calculation results were compared with the available reference data of similar Generation III Passive Water Reactor to assess the code's capability to predict the MSLB phenomena. The DAKOTA toolkit is used to drive both parameter sensitivity analysis and uncertainty propagation. The 95/95 uncertainty bands of key output parameters were obtained using the Wilks’ statistical methods.Compared with the reference data, the simulation results partially confirmed the stability and repeatability of the code model for initial and boundary condition perturbations. The uncertainty bands of important output parameters were demonstrated. The results indicated that the maximum containment pressure value was below the safety limit, and the passive safety system can mitigate the consequence of the MSLB. The mass and energy released into the containment were assessed according to the containment design.The parameter sensitivity analysis was performed with 34 input parameters, and the results were evaluated by Spearman's Simple Rank Correlation Coefficients.

AbstractDue to its vast industrial applications and biological context, the investigation of the inconsistent heat and mass transfer that drives the flow of squeezing viscous nanofluids between two plates is a fascinating topic. In this study, we investigated the heat transfer analysis of unsteady viscous nanofluid between two parallel plates. The partial differential equations illustrating the flow model are converted to nonlinear ordinary differential equations by suggesting similarity transformations. The resulting dimensionless and nonlinear ODEs of temperature functions and velocity are solved using the well know numerical technique shooting method by transforming the problem into initial value problem from boundary value problem. The results found are consistent with this numerical solution. Graphically explore the impacts of different parameters on temperature profiles and velocity. The results are compared with the results solved by HPM. The results concurred with this numerical solution. These findings are considered much be useful in the application of polymer processing, power transmission, compression, temporary loading of mechanical parts, food processing, cooling water, gravity machinery, modeling of plastic transport in vivo, chemical processing instruments, and demolition due to freezing.

Abstract It is well know that the two-fluid single pressure model is currently widely used to analyze reactor transient accidents such as LOCA. Current mainstream reactor safety analysis codes such as RALAP5 and CATHARE are based on this single pressure model. However this model has been proved to be ill posed in the sense that the equation system is non-hyperbolic which will lead to numerical unphysical oscillation. Currently reactor safety analysis codes use the interfacial pressure and virtual mass force to solve the ill-posed non-hyperbolicity issue. The development of China’s self-owned reactor high fidelity system analysis code has attracted much attention in recent years, and studying on the ill-posedness of the two-fluid model and the improvement of the ill-posedness is an important basis to analyze these reactor accidents. In this paper, the ill-posedness regions of the two-fluid single pressure model is first investigated using the eigenvalue analysis method based on the Cauchy problem with initial conditions. Then the effect of the virtual mass force and the interfacial pressure is studied by this eigenvalue analysis method, and three types of virtual mass term in the momentum equation are discussed. The results show that the appropriate virtual mass force and interfacial pressure can well improve the ill-posedness of the single pressure model, and the appropriate combination of them can significantly improve the ill-posedness.

Abstract Sabah block H, located in 1,300 meters of water depth at offshore Sabah, comprises Buluh and Rotan fields. The subsea production system, i.e., trees, jumpers, manifold, umbilicals, risers and flowlines were installed and tied back to an FLNG facility. After Block H achieved 1st gas in Feb-2021, one temperature sensor at downstream of Rotan P3 Subsea XMT failed post 6 days of operation. Replacing the physical transmitter is not practical as it is integrated at an unretrievable part of XMT. A drilling rig is required to pull the upper completion assembly of the well before retrieving the XMT to surface for repair and consider non-economic approach. The objective of the project was to develop a virtual sensor to monitor and control JT cooling effect at downstream of the subsea choke to avoid hydrate plugs during cold start operations. A Hysys equivalent flowpath model was developed to simulate the thermodynamic process. Gas composition, flow rates from the Multiphase Flow meter, Inlet and outlet pressure at subsea choke, gas mass fraction, Hydrate Inhibitor (MEG and MeOH) mass fraction as well as temperature profiles at the wellhead condition were input and integrated into the model. Four hybrid methods using semi-physics-based approaches were used to correlate the results from the Hysis model within the acceptable range of the energy balance in the expected Gas Mass Fraction (GMF). Other well data were subsequently used to validate the model including fine-tuning before the final acceptance test. After more than 500,000 data points were correlated with the initial choke model, some errors around 20% were observed in the transient flow period in the first round of validation. Therefore, sets of similar field data from the other nearby wells, i.e., Rotan P1 and P2 were used to further validate the predicted model and adjust some arbitrary constants to correlate the mass and energy balance in the expected GVF mode during the transient and stead state operation. The software acceptance test indicated the accuracy of less than 5% from the Choke model based on final validation data from Rotan P1 and P2. The real-time model was subsequently developed and successfully implemented into the subsea control system at offshore inside the Operator workstation, Integrated Virtualization Manager (IVM), and Master Control System (MCS). This subsea virtual sensor has been critically monitored during the cold start to prevent hydrate formation due to Joule Thompson (JT) Cooling at the downstream of the subsea Christmas Tree. As the lowest temperature was as low as -23C during the cold start, the operator would be able to bean back the choke and inject more hydrate inhibitors to alleviate the effect throughout the end of the field life. Block H has been inevitably operating in the hydrate formation zone. With high pressures from the deepwater gas well and low ambient temperature around 2C at seabed as well as pre-existing water given by aquifer driven mechanism in reservoir. The virtual temperature sensor is considered as a cost-effective solution to manage the JT Cooling during the cold start and avoid hydrate plugs at the subsea XMT. The field successfully achieved 100% of subsea production uptime in 2022.

This paper presents a computer-aided conceptual design system for developing product forms. The system integrates a virtual hand, which is manipulated by the designer, with deformable models representing the product forms. Designers can use gestural input and full hand pointing in the system to discover potential new ways for product form design. In the field of industrial design, styling and ergonomics are two important factors that determine a successful product design. Traditionally, designers explore possible concepts by sketching their ideas and then using clay or foam mock-ups to test them during the early phases of product design. With our deformable modeling simulation system, we provide a useful and efficient tool for industrial designers that enable to produce product form proposals efficiently without unnecessary trial and error. Designers can input pre-scanned 3D raw data or a 3D CAD model as an initial prototype. Then, the input model is given the material’s elastic property via the construction of a volume-like mass-spring-damping system. The virtual hand in the system constantly changes gestures as the designer manipulates it with a glove-based input device. The product form will be deformed or shaped according to the amount of force exerted by the virtual hand. A mesh smoothing feature called “PN-triangle” is also used to improve the appearance of the deformed model. Finally, a physical prototype with volume and weight is generated using a rapid prototyping machine. Designers can use these mock-ups to conduct further ergonomic evaluations.

Typical drivers are not ready to react to unexpected collisions from other vehicles. The initial impact can startle the driver who then fails to maintain control. Since a loss of control leads to intense skidding and undesirable lateral motions, more severe subsequent events are likely to occur. To reduce the severity of possible subsequent (secondary) crashes, this paper considers both vehicle heading angle and lateral deviation from the original driving path. The research concept here is different from today’s electronic stability control systems in that it activates the differential braking even when the magnitude of yaw rate or vehicle slip angle is very high. In addition, the lateral displacement and yaw angle with respect to the road are part of the control objective. The Linear Time Varying Model Predictive Control (LTV-MPC) method is used, with the key tire nonlinearities captured through linearization. We consider tire force constraints based on the combined-slip tire model and their dependence on vehicle motion. The computed high-level (virtual) control signals are realized through a control allocation problem which maps vehicle motion commands to tire braking forces considering constraints. Numerical simulation and analysis results are presented to demonstrate the effectiveness of the control algorithm.

Abstract Artificial Intelligence (AI) is relatively new neurocomputational science employed in oil industry to solve wide spectrum of non-linear problems with high parallelism, fault and noise tolerance. AI seems very attractive for its remarkable capabilities of processing-correlating data and learning attributes. This paper briefs a successful implementation of an ecosystem between AI and physics-based models in a smart field, that support accurate well allocation process during the project start-up when testing facilities were not available. This case study is presented in a smart field during the commissioning of a new phase-project incorporating 45 new strings at a time. Reconciliation between wells and fiscal meters vanished after incorporating the newly commissioned wells with no flow-tests. An innovative AI-model was developed to estimate well rates from real-time surface parameters (pressure, temperature, choke &gas lift rate) to assist the allocation process for those strings, utilizing extensive well test history and subsurface data from pre-existing nearby wells. Data mining and physics-based models were integrated to develop an ecosystem that can virtually measure daily oil, water and gas rates with reasonable accuracy enhancing well back-allocation process. Initial newly-strings models were built using only one commissioning test, consisting of diverting wells to a portable separator for few hours. This practice usually overestimates the productivity index since rates are captured in transient mode. Later, when wells are flowing for longer and cleaned up, production rates decrease after stabilization. Fortunately, these changes of performance over time are well-captured by the real time parameters. Therefore, this paper proposal can be extended to other digital fields to track the well performance and minimize the error in back allocated rates as it was observed in this field application, demonstrating how reconciliation factor was continuously enhanced day after day, once AI-virtual rate prediction was introduced. AI-model prediction was later verified against actual flow tests via portable separators with an average error below 20%. Virtual rates were predicted using machine learning (ML) techniques multilinear regression, Artificial Neural-Network (ANN) and Self-Organizing Maps (SOM). The results were used to update models for better well performance prediction. The performance of these ML techniques were improved with intelligent inputs and proper segregated and intuitive training to machine. As a practical application, an ecosystem was developed combining AI and physics to predict well-performance of newly-drill wells under gas lift and natural flow, using real-time measurement and the digital framework, to provides reasonably accurate in simulating both training and test time-dependent well performance inferred from pressure, temperature, gas-lift rate and choke. The novelty of this paper consists in the developed data cleansing and association technics that enable the implementation of successful AI-models in wells with no flow test data for training, levering Real-Time data usage.

<div class="section abstract"><div class="htmlview paragraph">The squeal noise is one of the critical factors to qualify a disc brake design from the Noise Vibration and Harshness (NVH) perspective. It is imperative to be watchful of the unstable natural modes of the brake assembly which trigger squeal. Any design modification for reducing a part’s contribution to targeted squeal mode can adversely affect and give rise to new squeal modes. Also, controlling conflicting requirements like mass, strength, and casting manufacturability, further adds up complexity, which increases design iterations and product cost. In view of these challenges, the application of the topological optimizations embedded under an artificial intelligence (AI) driven optimization workflow is explored. The scope of optimization is kept limited only to the caliper. Complex eigenvalue (EV) finite element analysis (FEA) of baseline design brake assembly is performed which predicts critical squeal mode having 34% strain energy contribution from caliper. To improve the squeal performance, surface morphing-based shape optimization with mode tracking is explored, which can be useful in the finetuning stages of the design. However, at the initial stages, topological optimizations play an important role in obtaining suitable concepts. Since commercial topological optimization tools do not support complex EV analysis, an integrated &amp; automated workflow is developed. In this, the caliper geometry is first topologically optimized for mass, stiffness, casting manufacturing constraints, followed by complex EV analysis of the optimized geometry. A dummy thermal analysis is included in topology optimization, which equivalently simulates irrotational inviscid fluid flow to improve casting filling performance. Furthermore, a computational fluid dynamics (CFD) solver is added to the workflow to simulate the viscous flow effects during filling process. AI based evolutionary multi-objective optimization algorithm is used to perform multi-disciplinary optimization on the caliper geometry. The best candidate obtained from virtual design iterations exhibited significant reduction in caliper’s strain energy contribution to 9% or less in squeal all modes, reduction in number of squeal modes while having better strength as compared to baseline design with controlled weight addition.</div></div>

The Naval Surface Warfare Center, Carderock Division replaced their 21 pneumatic type wavemaker domes with a 216-paddle directional wavemaker in the fall of 2013. This wavemaker is capable of producing regular waves at oblique angles to the wave banks as well as long crested and short crested irregular model seas. Another powerful capability of the new system is the ability to preview the commanded waves in 3D virtual space on the computer screen. The new directional wavemaker facility has been in operation for four years. Mixtures of capabilities exceeding the original requirements as well as unforeseen problems were encountered. Based upon the operational experience gained in the last four years lessons learned are presented. Going from 21 domes to 216 individual paddles has adverse consequences on maintenance and reliability. That in and of itself is just a consequence of requiring a more complex machine to make more complex waves – not really good or bad. Despite the initial concerns this wavemaker has proven to be reliable, easily maintainable and when required, easily repairable.

The Army’s modernization priorities include the development of augmented reality and virtual reality (AR/VR) simulations for enabling the regiment and increasing soldier readiness. The use of AR/VR technology at the U.S. Army Engineer Research and Development Center (ERDC) is also growing in the realm of military and civil works program missions. The ERDC Coastal and Hydraulics Laboratory (CHL) has developed a ship simulator to evaluate bay channels across the world; however, the current simulator has little to no physical realism in nearshore coastal regions (Figure 1). Thus, the ERDC team is researching opportunities to advance ship simulation to deliver the Ship Simulator of the Future (SSoF). The SSoF will be equipped with a VR mode and will more accurately resolve nearshore wave phenomena by ingesting precalculated output from a Boussinesq-type wave model. This initial prototype of the SSoF application is intended for research and development purposes; however, the technologies employed will be applicable to other disciplines and project scopes, including the Synthetic Training Environment (STE) and ship and coastal structure design in future versions.

PUPA is a computer program which predicts the critical loads of a long tube under external pressure and axial tension. The program takes into account the effect of inelastic material behaviour on collapse and could be used for tubes with diameter to thickness ratio as low as 10. The analysis is based on a principle of virtual work type of formulation and the resulting nonlinear equilibrium equations are solved using Newton-Raphson method. The model implemented considers a long tube under generalized plane strain conditions and uniform ovalization. Effect of initial ovality, residual stresses and anisotropic yielding can be included.

Phase II of the project has focused on improving the initial analysis performed in the first phase by enhancing the various aspects of predictive combustion for lean burn spark ignition natural gas engines under variable composition fueling. These enhancements have incorporated validation data from a Cooper-Bessemer GMVH-10C3 engine located in New Jersey, which improves upon the lack of field data to bound the scope of composition variation. In simulation related endeavors, effort was made to improve the fundamental combustion physics related parameters, namely laminar flame speed, by developing a code base for distributed computing of the chemical kinetics solver, Cantera, and was key to improving upon the chemistry modeling used in the previous phase. Methods to improve numerical convergence were employed to reduce the time to solve large mechanisms, such as the Saudi Aramco Mechanism (v1.3). Modeling of pre-chamber combustion from first principles, common input experimental heat release analysis and simulated heat release generation were additional components of improving model matching with pre-chambered engines. In its current state, manual optimization is required to tune the heat release curves based on guesses about the initial charge mass state, scavenging efficiency, fuel delivery and thereby the trapped equivalence ratio.

Silica fume (SF) influences the hydration rate of Portland cement in different ways depending on the physical and chemical properties of the SF. This study reports the impact of SiO2 content (%), loss on ignition (%), and Brunauer–Emmett–Teller (BET) specific surface area on the hydration reaction of SF-cement paste mixtures. This study used five types of SFs with varying SiO2 content, loss on ignition (%), and particle morphology. Five SFs were mixed with Class H oil well cement at each of two different replacement levels (20% or 30% by mass), and the released heat of hydration was measured using isothermal calorimetry. The results were used to improve the pozzolanic reaction simulation feature of the original Virtual Cement and Concrete Testing Laboratory (VCCTL) software, which enabled the soft-ware to simulate a higher SF replacement ratio in a cement mixture with higher fidelity. Results showed that a silica fume’s SiO2 content (%), loss on ignition (%), and BET specific surface area significantly influence the heat release rate. The new simulation model agrees well with the measurements on all the pastes tested.

The article deals with the mental-existential relationship between ethnoculture, national identity and media culture as a necessary factor for their preservation, transformation, on the example of national original algorithms, matrix models, taking into account global tendencies and Ukrainian archetypal-specific features in Ukraine. the media actively serve the domestic oligarchs in their information-virtual and real wars among themselves and the same expansive alien humanitarian acts by curtailing ethno-cultural programs-projects on national radio, on television, in the press, or offering the recipient instead of a pop pointer, without even communicating to the audience the information stipulated in the media laws − information support-protection-development of ethno-culture national product in the domestic and foreign/diaspora mass media, the support of ethnoculture by NGOs and the state institutions themselves. In the context of the study of the cultural national socio-humanitarian space, the article diagnoses and predicts the model of creating and preserving in it the dynamic equilibrium of the ethno-cultural space, in which the nation must remember the struggle for access to information and its primary sources both as an individual and the state as a whole, culture the transfer of information, which in the process of globalization is becoming a paramount commodity, an egregore, and in the post-traumatic, interrupted-compensatory cultural-information space close rehabilitation mechanisms for national identity to become a real factor in strengthening the state − and vice versa in the context of adequate laws («Law about press and other mass media», Law «About printed media (press) in Ukraine», Law «About Information», «Law about Languages», etc.) and their actual effect in creating motivational mechanisms for preserving/protecting the Ukrainian language, as one of the main identifiers of national identity, information support for its expansion as labels cultural and geostrategic areas.

As the most widely used construction material, concrete is very durable and can provide long service life without extensive maintenance. The strength and durability of concrete are primarily influenced by the initial water-cement ratio value (w/c), and the curing condition during the hardening process also influences its performance. The w/c value is defined as the total mass of free water that can be consumed by hydration divided by the total mass of cement and any additional pozzolanic material such as fly ash, slag, silica fume. Once placed, field concrete pavements are routinely cured with liquid membrane-forming compounds. For laboratory study, concrete samples are usually cured in saturated lime water or a curing room with a relative humidity (RH) value higher than 95%. Thus, the effectiveness of curing compounds for field concrete needs to be studied. In this study, the dielectric constant value of plastic concrete was measured by ground penetrating radar (GPR). The w/c value of the plastic concrete was calculated by a mathematical model from the measured dielectric constant value. The calculated w/c value was compared with the microwave oven drying measurement determined result in AASHTO T318. A modified coarse aggregate correction factor was proposed and applied in microwave oven drying measurement to determine the w/c value of plastic concrete in AASHTO T318. The effectiveness of curing compound was evaluated by field concrete slabs by GPR measurement. It was found that GPR can be a promising NDT method for In this study, the dielectric constant value of plastic concrete was measured by ground penetrating radar (GPR). The w/c value of the plastic concrete was calculated by a mathematical model from the measured dielectric constant value. The calculated w/c value was compared with the microwave oven drying measurement determined result in AASHTO T318. A modified coarse aggregate correction factor was proposed and applied in microwave oven drying measurement to determine the w/c value of plastic concrete in AASHTO T318. The effectiveness of curing compound was evaluated by field concrete slabs by GPR measurement. It was found that GPR can be a promising NDT method for w/c determination of plastic concrete and curing effectiveness evaluation method for hardened concrete.

Offshore wind farms typically host tens to hundreds of turbines that are individually sited on foundations or anchored if floating. These are connected by inter-farm cables which feed into one or more marine-based substations, further feeding one or more shore-connected high-voltage cables - all infrastructure that requires knowledge of water depth, metocean conditions, and seabed/subsurface geology. With this industry set to establish itself on the continental shelf of Atlantic Canada, knowledge of the geological conditions from the seabed to tens of metres below will be essential for farm layout and foundation design. Thus, geoscience questions addressing regional geomorphology, Pleistocene glacial retreat and sea-level change, the characteristics of key individual stratigraphic layers, and the magnitude and patterns of sediment mobility are important. In Atlantic Canada, ongoing efforts to address these questions are using legacy data, but new data is required to further our understanding of the shallower portions of the shelf. Examples include: what is the distribution of buried tunnel valleys under offshore banks, and might their complex facies infill affect foundation conditions? How and where would the organic sediments, left by a coastal suite of landforms drowned during transgression, affect foundation or landfalling cable stability? How active is salt diapirism, and could it be considered a geohazard? Are demonstrated sediment mass failures also a risk? What is the current understanding of sediment mobility in shallow waters, and how does that affect infrastructure armouring/depth of burial? What is the variability of the geotechnical properties of our offshore sediments? What is the foundation suitability of offshore Tertiary semi-consolidated bedrock? To conclude, the initial scope of a developing regional foundation suitability model will be presented for the Eastern Scotian Shelf.

An experimental study was carried out to characterize the scavenging behavior of a cross-scavenged, piston-aspirated, two-stroke, natural gas engine to aid in the development of computationally inexpensive simple scavenging models for onboard engine control by (1) studying the effects of changing operational parameters on the engine's scavenging performance, and (2) identifying the underlying phenomena driving the observed effects. Tracer based methods were used to quantify the scavenging and trapping performance of the engine - CO2 was used as a tracer for combustion products and pre-mixed fuel was used as a fresh charge tracer. CO2 concentration was measured on a crank angle resolved basis both in the engine cylinder and exhaust using portable NDIR sensors, while unburned fuel concentration was measured in the exhaust using the FID module of a standard five gas analyzer. It was found that scavenging took place in three stages, an initial perfect displacement type stage, followed by a short-circuiting, and a perfect mixing type stage. Engine speed and load changes were found to have the strongest effects on the trapping and scavenging performance of the engine; spark timing effects were less significant. Changes in measured scavenging and trapping efficiencies at different operating points resulted from a combination of influences, namely (1) reduced time for gas exchange at high speeds, (2) higher expansion and scavenging pressures at high loads and retarded spark timings, and (3) phasing of the reflected 'scavenging' and 'plugging' pulses in the exhaust pipe relative to BDC and EPC, respectively. Increasing engine load made the engine scavenge significantly better and increasing engine speed resulted in a larger fraction of the delivered air being trapped. The combined effect of these scavenging changes and changes in the engine's fuel conversion efficiency resulted in the engine running leaner at high speeds (more air delivered and higher trapping efficiency) and at low loads (higher trapped residuals). The results were then used to gauge the performance of the simple scavenging model (the hybrid model) developed in phase II of the project. While encouraging results were obtained at high speed, the trapped air mass was overestimated at medium speed; suggesting the need for adding a low scavenging efficiency sub-model. Recommendations have been made about adding a short-circuiting zone to address this limitation of the model.

Background: Public behaviour and the new hostile threats • Civil contingencies planning and preparedness for hostile threats requires accurate and up to date knowledge about how the public might behave in relation to such incidents. Inaccurate understandings of public behaviour can lead to dangerous and counterproductive practices and policies. • There is consistent evidence across both hostile threats and other kinds of emergencies and disasters that significant numbers of those affected give each other support, cooperate, and otherwise interact socially within the incident itself. • In emergency incidents, competition among those affected occurs in only limited situations, and loss of behavioural control is rare. • Spontaneous cooperation among the public in emergency incidents, based on either social capital or emergent social identity, is a crucial part of civil contingencies planning. • There has been relatively little research on public behaviour in response to the new hostile threats of the past ten years, however. • The programme of work summarized in this briefing document came about in response to a wave of false alarm flight incidents in the 2010s, linked to the new hostile threats (i.e., marauding terrorist attacks). • By using a combination of archive data for incidents in Great Britain 2010-2019, interviews, video data analysis, and controlled experiments using virtual reality technology, we were able to examine experiences, measure behaviour, and test hypotheses about underlying psychological mechanisms in both false alarms and public interventions against a hostile threat. Re-visiting the relationship between false alarms and crowd disasters • The Bethnal Green tube disaster of 1943, in which 173 people died, has historically been used to suggest that (mis)perceived hostile threats can lead to uncontrolled ‘stampedes’. • Re-analysis of witness statements suggests that public fears of Germany bombs were realistic rather than unreasonable, and that flight behaviour was socially structured rather than uncontrolled. • Evidence for a causal link between the flight of the crowd and the fatal crowd collapse is weak at best. • Altogether, the analysis suggests the importance of examining people’s beliefs about context to understand when they might interpret ambiguous signals as a hostile threat, and that. Tthe concepts of norms and relationships offer better ways to explain such incidents than ‘mass panic’. Why false alarms occur • The wider context of terrorist threat provides a framing for the public’s perception of signals as evidence of hostile threats. In particular, the magnitude of recent psychologically relevant terrorist attacks predicts likelihood of false alarm flight incidents. • False alarms in Great Britain are more likely to occur in those towns and cities that have seen genuine terrorist incidents. • False alarms in Great Britain are more likely to occur in the types of location where terrorist attacks happen, such as shopping areass, transport hubs, and other crowded places. • The urgent or flight behaviour of other people (including the emergency services) influences public perceptions that there is a hostile threat, particularly in situations of greater ambiguity, and particularly when these other people are ingroup. • High profile tweets suggesting a hostile threat, including from the police, have been associated with the size and scale of false alarm responses. • In most cases, it is a combination of factors – context, others’ behaviour, communications – that leads people to flee. A false alarm tends not to be sudden or impulsive, and often follows an initial phase of discounting threat – as with many genuine emergencies. 2.4 How the public behave in false alarm flight incidents • Even in those false alarm incidents where there is urgent flight, there are also other behaviours than running, including ignoring the ‘threat’, and walking away. • Injuries occur but recorded injuries are relatively uncommon. • Hiding is a common behaviour. In our evidence, this was facilitated by orders from police and offers from people staff in shops and other premises. • Supportive behaviours are common, including informational and emotional support. • Members of the public often cooperate with the emergency services and comply with their orders but also question instructions when the rationale is unclear. • Pushing, trampling and other competitive behaviour can occur,s but only in restricted situations and briefly. • At the Oxford Street Black Friday 2017 false alarm, rather than an overall sense of unity across the crowd, camaraderie existed only in pockets. This was likely due to the lack of a sense of common fate or reference point across the incident; the fragmented experience would have hindered the development of a shared social identity across the crowd. • Large and high profile false alarm incidents may be associated with significant levels of distress and even humiliation among those members of the public affected, both at the time and in the aftermath, as the rest of society reflects and comments on the incident. Public behaviour in response to visible marauding attackers • Spontaneous, coordinated public responses to marauding bladed attacks have been observed on a number of occasions. • Close examination of marauding bladed attacks suggests that members of the public engage in a wide variety of behaviours, not just flight. • Members of the public responding to marauding bladed attacks adopt a variety of complementary roles. These, that may include defending, communicating, first aid, recruiting others, marshalling, negotiating, risk assessment, and evidence gathering. Recommendations for practitioners and policymakers • Embed the psychology of public behaviour in emergencies in your training and guidance. • Continue to inform the public and promote public awareness where there is an increased threat. • Build long-term relations with the public to achieve trust and influence in emergency preparedness. • Use a unifying language and supportive forms of communication to enhance unity both within the crowd and between the crowd and the authorities. • Authorities and responders should take a reflexive approach to their responses to possible hostile threats, by reflecting upon how their actions might be perceived by the public and impact (positively and negatively) upon public behaviour. • To give emotional support, prioritize informative and actionable risk and crisis communication over emotional reassurances. • Provide first aid kits in transport infrastructures to enable some members of the public more effectively to act as zero responders.