Search results for: wake dynamics

Authors: John Knight, Fuchun Li, Yan Xu

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Based on a new method of the nonparametric estimator of the drift function, we propose a consistent test for the parametric specification of the drift function in the short rate diffusion process using observations from a panel of yields. The test statistic is shown to follow an asymptotic normal distribution under the null hypothesis that the parametric drift function is correctly specified, and converges to infinity under the alternative. Taking the daily 7-day European rates as a proxy of the short rate, we use our test to examine whether the drift of the short rate diffusion process is linear or nonlinear, which is an unresolved important issue in the short rate modeling literature. The testing results indicate that none of the drift functions in this literature adequately captures the dynamics of the drift, but nonlinear specification performs better than the linear specification.

Keywords: diffusion process, nonparametric estimation, derivative security price, drift function and volatility function

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Authors: Bo Kampmann Walther

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This essay examines the narratives of the Book of Genesis through the lens of game theory, a mathematical framework for analyzing strategic interactions among rational actors. By treating key figures in Genesis as players in a game, this analysis sheds light on their decisions and the resulting consequences. Focusing primarily on the story of Adam and Eve, the essay utilizes concepts such as game state, saddle point, optimal strategy, and Nash equilibrium to explore the dynamics at play and scrutinize the existence of two kinds of game rules in Genesis: one being global and post-Fall oriented, the other being local and relegated to life in the Garden. The serpent's intervention and the subsequent actions of Adam and Eve are modeled as strategic moves, revealing the complexities and shifts in the game state from harmony in Eden to a world marked by toil and mortality post-Fall.

Keywords: game theory, Genesis, strategy, saddle point, nash equilibrium, New Game State

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Authors: Tanu Aneja, Harsha Malaviya

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Capturing pose information in cricket shots poses several challenges, such as low-resolution videos, noisy data, and joint occlusions caused by the nature of the shots. In response to these challenges, we propose a CondDGConv-based framework specifically for cricket shot prediction. By analyzing the spatial-temporal relationships in batsman shot sequences from an annotated 2D cricket dataset, our model achieves a 97% accuracy in predicting shot types. This performance is made possible by conditioning the graph network on batsman 2D poses, allowing for precise prediction of shot outcomes based on pose dynamics. Our approach highlights the potential for enhancing shot prediction in cricket analytics, offering a robust solution for overcoming pose-related challenges in sports analysis.

Keywords: action recognition, cricket. sports video analytics, computer vision, graph convolutional networks

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Authors: G. Carrero, C. Contreras, M. J. Hendzel

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Linker histones or histones H1 are highly mobile nuclear proteins that regulate the organization of chromatin and limit DNA accessibility by binding to the chromatin structure (DNA and associated proteins). It is known that this binding process is driven by both slow (strong binding) and rapid (weak binding) interactions. However, the exact binding mechanism has not been fully described. Moreover, the existing models only account for one type of bound population that does not distinguish explicitly between the weakly and strongly bound proteins. Thus, we propose different systems of reaction-diffusion equations to describe explicitly the rapid and slow interactions during a FRAP (Fluorescence Recovery After Photobleaching) experiment. We perform a model comparison analysis to characterize the binding mechanism of histone H1 and provide new meaningful biophysical information on the kinetics of histone H1.

Keywords: FRAP (Fluorescence Recovery After Photobleaching), histone H1, histone H1 binding kinetics, linker histone, reaction-diffusion equation

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Authors: Olivier Delage, Thierry Portafaix, Hassan Bencherif, Guillaume Guimbretiere

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Most observation data sequences in geophysics can be interpreted as resulting from the interaction of several physical processes at several time and space scales. As a consequence, measurements time series in geophysics have often characteristics of non-linearity and non-stationarity and thereby exhibit strong fluctuations at all time-scales and require a time-frequency representation to analyze their variability. Empirical Mode Decomposition (EMD) is a relatively new technic as part of a more general signal processing method called the Hilbert-Huang transform. This analysis method turns out to be particularly suitable for non-linear and non-stationary signals and consists in decomposing a signal in an auto adaptive way into a sum of oscillating components named IMFs (Intrinsic Mode Functions), and thereby acts as a bank of bandpass filters. The advantages of the EMD technic are to be entirely data driven and to provide the principal variability modes of the dynamics represented by the original time series. However, the main limiting factor is the frequency resolution that may give rise to the mode mixing phenomenon where the spectral contents of some IMFs overlap each other. To overcome this problem, J. Gilles proposed an alternative entitled “Empirical Wavelet Transform” (EWT) which consists in building from the segmentation of the original signal Fourier spectrum, a bank of filters. The method used is based on the idea utilized in the construction of both Littlewood-Paley and Meyer’s wavelets. The heart of the method lies in the segmentation of the Fourier spectrum based on the local maxima detection in order to obtain a set of non-overlapping segments. Because linked to the Fourier spectrum, the frequency resolution provided by EWT is higher than that provided by EMD and therefore allows to overcome the mode-mixing problem. On the other hand, if the EWT technique is able to detect the frequencies involved in the original time series fluctuations, EWT does not allow to associate the detected frequencies to a specific mode of variability as in the EMD technic. Because EMD is closer to the observation of physical phenomena than EWT, we propose here a new technic called EAWD (Empirical Adaptive Wavelet Decomposition) based on the coupling of the EMD and EWT technics by using the IMFs density spectral content to optimize the segmentation of the Fourier spectrum required by EWT. In this study, EMD and EWT technics are described, then EAWD technic is presented. Comparison of results obtained respectively by EMD, EWT and EAWD technics on time series of ozone total columns recorded at Reunion island over [1978-2019] period is discussed. This study was carried out as part of the SOLSTYCE project dedicated to the characterization and modeling of the underlying dynamics of time series issued from complex systems in atmospheric sciences

Keywords: adaptive filtering, empirical mode decomposition, empirical wavelet transform, filter banks, mode-mixing, non-linear and non-stationary time series, wavelet

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Authors: Mohammad Nazififard, Reihane Faghihi

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This paper is aimed at understanding convective heat transfer of enclosed phase change material (PCM) in the solar and low-temperature hot water radiant floor heating geometry. In order to obtain the best performance of PCM, a radiant heating structure of the energy storage floor is designed which places heat pipes in the enclosed phase change material (PCM) layer, without concrete in it. The governing equations are numerically solved. The PCM thermal storage time is considered in relation to the floor surface temperature under different hot water temperatures. Moreover the PCM thermal storage time is numerically estimated under different supply water temperatures and flow rate. Results show the PCM floor heating system has a potential of making use of the daytime solar energy for heating at night efficiently.

Keywords: solar floor, heating system, phase change material, computational fluid dynamics

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Authors: Gleda Kutrolli, Maksi Kutrolli, Etjon Meco

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SARS-CoV-2 virus is currently one of the most infectious pathogens for humans. It started in China at the end of 2019 and now it is spread in all over the world. The origin and diffusion of the SARS-CoV-2 epidemic, is analysed based on the discussion of viral phylogeny theory. With the aim of understanding the spread of infection in the affected countries, it is crucial to modelize the spread of the virus and simulate its activity. In this paper, the prediction of coronavirus outbreak is done by using SIR model without vital dynamics, applying different numerical technique solving ordinary differential equations (ODEs). We find out that ABM and MRT methods perform better than other techniques and that the activity of the virus will decrease in April but it never cease (for some time the activity will remain low) and the next cycle will start in the middle July 2020 for Norway and Denmark, and October 2020 for Sweden, and September for Finland.

Keywords: forecasting, ordinary differential equations, SARS-COV-2 epidemic, SIR model

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Authors: Lesley Clack, Rachel Ellison, Elizabeth Chambers

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A belief exists that there are huge gender and racial disparities among hospital CEO’s in the United States, and historically, male, Caucasian healthcare executives have made significantly larger salaries than females and other races. With a recent focus on reducing barriers and disparities in healthcare, it remains to be seen whether there have been changes in these disparities over time. The purpose of this study was to explore disparities among salaries of hospital executives in the United States. Analysis of salary data was conducted utilizing online hospital salary databases. Statistical analysis was conducted to examine the significance of the differences. Results indicated that there had been improvements in disparities among some ethnicities. Gender disparities remain the largest gap. The implications of this study are significant for the field of healthcare management as disparities can affect both social dynamics and organizational culture. Understanding where disparities lie is the first step towards bridging the gap and reducing barriers for cultural diversity within healthcare management.

Keywords: health care, disparities, management, executives

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Authors: Jossitt Williams Vargas Cruz, Aura Jazmín Pérez Ríos

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The variations of solar dynamics have become a relevant topic of study due to the effects of climate changes generated on the earth. One of the most disconcerting aspects is the variability that the sun has on the climate is the role played by sunspots (extra-atmospheric variable) in the modulation of the Cosmic Rays CR (extra-atmospheric variable). CRs influence the earth's climate by affecting cloud formation (atmospheric variable), and solar cycle influence is associated with the presence of solar storms, and the magnetic activity is greater, resulting in less CR entering the earth's atmosphere. The different methods of climate prediction in Colombia do not take into account the extra-atmospheric variables. Therefore, correlations between atmospheric and extra-atmospheric variables were studied in order to implement a Python code based on neural networks to make the prediction of the extra-atmospheric variable with the highest correlation.

Keywords: correlations, cosmic rays, sun, sunspots and variations.

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Authors: Omonov Jahongir Mahmatkulovic

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Purpose: To study the significance of D-dimer (DD), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen coagulation parameters (Fg) in predicting the course, severity and prognosis of COVID-19. Source and method of research: From September 15, 2021, to November 5, 2021, 93 patients aged 25 to 60 with suspected COVID-19, who are under inpatient treatment at the multidisciplinary clinic of the Tashkent Medical Academy, were retrospectively examined. DD, PT, APTT, and Fg were studied in dynamics and studied changes. Results: Coagulation disorders occurred in the early stages of COVID-19 infection with an increase in DD in 54 (58%) patients and an increase in Fg in 93 (100%) patients. DD and Fg levels are associated with the clinical classification. Of the 33 patients who died, 21 had an increase in DD in the first laboratory study, 27 had an increase in DD in the second and third laboratory studies, and 15 had an increase in PT in the third test. The results of the ROC analysis of mortality showed that the AUC DD was three times 0.721, 0.801, and 0.844, respectively; PT was 0.703, 0.845, and 0.972. (P<0:01). Conclusion”: Coagulation dysfunction is more common in patients with severe and critical conditions. DD and PT can be used as important predictors of mortality from COVID-19.

Keywords: Covid19, DD, PT, Coagulogram analysis, APTT

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Authors: William Anderson, Kyle Kobold, Oleg Yakimenko

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Green microgrids using mostly renewable energy (RE) for generation, are complex systems with inherent nonlinear dynamics. Among a variety of different optimization tools there are only a few ones that adequately consider this complexity. This paper evaluates applicability of two somewhat similar optimization tools tailored for standalone RE microgrids and also assesses a machine learning tool for performance prediction that can enhance the reliability of any chosen optimization tool. It shows that one of these microgrid optimization tools has certain advantages over another and presents a detailed routine of preparing input data to simulate RE microgrid behavior. The paper also shows how neural-network-based predictive modeling can be used to validate and forecast solar power generation based on weather time series data, which improves the overall quality of standalone RE microgrid analysis.

Keywords: microgrid, renewable energy, complex systems, optimization, predictive modeling, neural networks

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Authors: Sihame Amakrane, Zineb Ouahdi, Mohammed Salah, Said Belaaouad

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\This research explores the efficacy of novel pyrimidine derivatives on bacterial strains such as Escherichia coli, Staphylococcus aureus, and Myccobacterium tuberculosis, utilizing bending energy calculations. Of the 25 compounds examined, 13 displayed potent activity against all the bacterial strains under study, exhibiting bending energy measurements between -7.4 and -10.7 kcal/mol. The -7.4 kcal/mol value corresponds to the bending energy of the SA12 and SA13 compounds with the 2xct protein (Staphylococcus aureus), whereas the -10.7 kcal/molis linked with the bending energy of SA6 and SA11 compounds with the 6GAV protein (Myccobacterium tuberculosis). Further research will involve a QSAR (Quantitative Structure-Activity Relationship) study aimed at constructing a reliable model to combat the aforementioned bacterial strains and a molecular dynamics study to evaluate the stability of ligand-protein complexes.

Keywords: docking, QSAR, bending energy, e. coli

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Authors: Ihsane Modhaffar, Kamal Gueraoui, Abouelkacem Qais, Abderrahmane Maaouni, Samir Men-La-Yakhaf, Hamid Eltourroug

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The main objective of this paper is to develop a Computational Fluid Dynamics (CFD) model to simulate and characterize the fiber suspension in flow in rectangular cavities. The model is intended to describe the velocity profile and to predict the fiber orientation. The flow was considered to be incompressible, and behave as Newtonian fluid containing suspensions of short-fibers. The numerical model for determination of velocity profile and fiber orientation during mold-filling stage of injection molding process was solved using finite volume method. The governing equations of this problem are: the continuity, the momentum and the energy. The obtained results were compared to available experimental findings. A good agreement between the numerical results and the experimental data was achieved.

Keywords: injection, composites, short-fiber reinforced thermoplastics, fiber orientation, incompressible fluid, numerical simulation

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Authors: William Casto

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Studies that consider the actual impact of international law upon foreign affairs crises are flawed by an unrealistic model of decision making. The common, unexamined assumption is that a nation has a unitary executive or ruler who considers a wide variety of considerations, including international law, in attempting to resolve a crisis. To the extent that negotiation theory is considered, the focus is on negotiations between or among nations. The unsettling result is a shallow focus that concentrates on each country’s public posturing about international law. The country-to-country model ignores governments’ internal negotiations that lead to their formal position in a crisis. The model for foreign policy crises needs to be supplemented to include a model of internal negotiations. Important foreign policy decisions come from groups within a government committee, advisers, etc. Within these groups, participants may have differing agendas and resort to international law to bolster their positions. To understand the influence of international law in international crises, these internal negotiations must be considered. These negotiations are crucial to creating a foreign policy agenda or recommendations. External negotiations between the two nations are significant, but the internal negotiations provide a better understanding of the actual influence of international law upon international crises. Discovering the details of specific internal negotiations is quite difficult but not necessarily impossible. The present proposal will use a specific crisis to illustrate the role of international law. In 1861 during the American Civil War, a United States navy captain stopped a British mail ship and removed two ambassadors of the rebelling southern states. The result was what is commonly called the Trent Affair. In the wake of the captain’s unauthorized and rash action, Great Britain seriously considered going to war against the United States. A detailed analysis of the Trent Affair is possible using the available and extensive internal British correspondence and memoranda to reach an understanding of the effect of international law upon decision making. The extensive trove of internal British documents is particularly valuable because in 1861, the only effective means of communication was face-to-face or through letters. Telephones did not exist, and travel by horse and carriage was tedious. The British documents tell us how individual participants viewed the process. We can approach an accurate understanding of what actually happened as the British government strove to resolve the crisis. For example, British law officers initially concluded that the American captain’s rash act was permissible under international law. Later, the law officers revised their opinion. A model of internal negotiation is particularly valuable because it strips away nations’ public posturing about disputed international law principles. In internal decision making, there is room for meaningful debate over the relevant principles. This fluid debate tells how international law is used to develop a hard, public bargaining position. The Trent Affair indicates that international law had an actual influence upon the crisis and that law was not mere window dressing for the government’s public position.

Keywords: foreign affairs crises, negotiation, international law, Trent affair

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Authors: Huizi Zeng

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This paper delineates the historical retrospective and current status of school choice in China. Focusing on analyzing the similarities and differences in origin, evolution, public dispute, policy dynamics between China and the United States, the article depicts a panorama and explores possible causes. Both China and the United States continue to learn from historical legacy and invent new programs to perfect school choice policy but the outcomes are so different. On the one hand, the percentage of public schools in China remains high all along, while there is a considerably significant reduction in the United States. On the other hand, there is more governmental intervention in the United States with continuous and constant policy updates and adjustment. Finally, this article adopts public-private partnerships (PPP) to seek to provide insights into differences between the two countries and argue that school choice is not only the production of education marketization and corporation but also driven by political mechanism.

Keywords: China, United States, school choice, comparative analysis, policy, public private partnerships

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Authors: Mohamed M. Abo Elazm, Ali I. Shehata, Mohamed M. Khairat Dawood

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A computational fluid dynamics (CFD) program FLUENT has been used to predict the fluid flow and heat transfer distribution within concentric heat exchangers. The effect of inlet inclination angle has been investigated with Reynolds number range (3000 – 4000) and Pr=0.71. The heat exchanger is fabricated from copper concentric inner tube with a length of 750 mm. The effects of hot to cold inlet flow rate ratio (MH/MC), Reynolds's number and of inlet inclination angle of 30°, 45°, 60° and 90° are considered. The results showed that the numerical prediction shows a good agreement with experimental measurement. The results present an efficient design of concentric tube heat exchanger to enhance the heat transfer by increasing the swirling effect.

Keywords: heat transfer, swirling effect, CFD, inclination angle, concentric tube heat exchange

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Authors: Tine Cencič, Marko Hočevar, Brane Širok

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An experimental investigation has been made to detect cavitation in pump–storage hydro power plant prototype suffering from cavitation in pump mode. Vibrations and acoustic emission on the housing of turbine bearing and pressure fluctuations in the draft tube were measured and the corresponding signals have been recorded and analyzed. The analysis was based on the analysis of high-frequency content of measured variables. The pump-storage hydro power plant prototype has been operated at various input loads and Thoma numbers. Several estimators of cavitation were evaluated according to coefficient of determination between Thoma number and cavitation estimators. The best results were achieved with a compound discharge coefficient cavitation estimator. Cavitation estimators were evaluated in several intervals of frequencies. Also, a prediction of cavitation erosion was made in order to choose the appropriate maintenance and repair periods.

Keywords: cavitation erosion, turbine, cavitation measurement, fluid dynamics

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Authors: Ishtiaq A. Chaudhry, Zia R. Tahir, F. A. Siddiqui, F. Noor, M. J. Rashid

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It has experimentally been proved that the performance of compression ignition (CI) engine is spray characteristics related. In modern diesel engine the spray formation and the eventual combustion process are the vital processes that offer more challenges towards enhancing the engine performance. In the present work, the numerical simulation has been carried out for evaporating diesel sprays using Fluent software. For computational fluid dynamics simulation “Meshing” is done using Gambit software before transmitting it into fluent. The simulation is carried out using hot bomb conditions under varying chamber conditions such as gas pressure, nozzle diameter and fuel injection pressure. For comparison purpose, the numerical simulations the chamber conditions were kept the same as that of the experimental data. At varying chamber conditions the spray penetration rates are compared with the existing experimental results.

Keywords: evaporating diesel sprays, penetration rates, hot bomb conditions

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Authors: Gilbert Makanda

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The problem of the teaching of mathematics is studied using differential equations. A mathematical model for knowledge acquisition in mathematics is developed. In this study we adopt the mathematical model that is normally used for disease modelling in the teaching of mathematics. It is assumed that teaching is 'infecting' students with knowledge thereby spreading this knowledge to the students. It is also assumed that students who gain this knowledge spread it to other students making disease model appropriate to adopt for this problem. The results of this study show that increasing recruitment rates, learning contact with teachers and learning materials improves the number of knowledgeable students. High dropout rates and forgetting taught concepts also negatively affect the number of knowledgeable students. The developed model is then solved using Matlab ODE45 and \verb"lsqnonlin" to estimate parameters for the actual data.

Keywords: differential equations, knowledge acquisition, least squares, dynamical systems

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Authors: Yul Y. Nazaruddin, Anas Y. Widiaribowo, Satriyo Nugroho

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Boiler is one of the critical unit in a petrochemical plant. Steam produced by the boiler is used for various processes in the plant such as urea and ammonia plant. An alternative method to optimize the boiler combustion system is presented in this paper. Adaptive Neuro-Fuzzy Inference System (ANFIS) approach is applied to model the boiler using real-time operational data collected from a boiler unit of the petrochemical plant. Nonlinear equation obtained is then used to optimize the air to fuel ratio using Genetic Algorithm, resulting an optimal ratio of 15.85. This optimal ratio is then maintained constant by ratio controller designed using inverse dynamics based on ANFIS. As a result, constant value of oxygen content in the flue gas is obtained which indicates more efficient combustion process.

Keywords: ANFIS, boiler, combustion process, genetic algorithm, optimization.

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Authors: A. Jomartov, A. Tuleshov, B. Tultaev

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One of the main tasks in the development of textile machinery is to increase the rapidity of automatic looms, and consequently, their productivity. With increasing automatic loom speeds, the dynamic loads on their separate mechanisms and moving joints sharply increase. Dynamic research allows us to determine the weakest mechanisms of the automatic loom. The modern automatic loom consists of a large number of structurally different mechanisms. These are cam, lever, gear, friction and combined cyclic mechanisms. The modern automatic loom contains various mechatronic devices: A device for the automatic removal of faulty weft, electromechanical drive warp yarns, electronic controllers, servos, etc. In the paper, we consider the multibody dynamic model of the automatic loom on the software complex SimulationX. SimulationX is multidisciplinary software for modeling complex physical and technical facilities and systems. The multibody dynamic model of the automatic loom allows consideration of: The transition processes, backlash at the joints and nodes, the force of resistance and electric motor performance.

Keywords: automatic loom, dynamics, model, multibody, SimulationX

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Authors: Emiliano Castillo

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The aim of this research is to analyze the origins, the development and possible outcomes of the environmental conflict between grassroots organizations, indigenous communities, Kinder Morgan Corporation, and the Canadian government over the Trans Mountain pipeline expansion in Burnaby, British Columbia, Canada. Building on the political ecology and the environmental justice theoretical framework, this research examines the impacts and risks of tar sands extraction, production, and transportation on climate change, public health, the environment, and indigenous people´s rights over their lands. This study is relevant to the environmental justice and political ecology literature because it discusses the unequal distribution of environmental costs and economic benefits of tar sands development; and focuses on the competing interests, needs, values, and claims of the actors involved in the conflict. Furthermore, it will shed light on the context, conditions, and processes that lead to the organization and mobilization of a grassroots movement- comprised of indigenous communities, citizens, scientists, and non-governmental organizations- that draw significant media attention by opposing the Trans Mountain pipeline expansion. Similarly, the research will explain the differences and dynamics within the grassroots movement. This research seeks to address the global context of the conflict by studying the links between the decline of conventional oil production, the rise of unconventional fossil fuels (e.g. tar sands), climate change, and the struggles of low-income, ethnic, and racial minorities over the territorial expansion of extractive industries. Data will be collected from legislative documents, policy and technical reports, scientific journals, newspapers articles, participant observation, and semi-structured interviews with representatives and members of the grassroots organizations, indigenous communities, and Burnaby citizens that oppose the Trans Mountain pipeline. These interviews will focus on their perceptions of the risks of the Trans Mountain pipeline expansion; the roots of the anti-tar sands movement; the differences and dynamics within the movement; and the strategies to defend the livelihoods of local communities and the environment against tar sands development. This research will contribute to the understanding of the underlying causes of the environmental conflict between the Canadian government, Kinder Morgan, and grassroots organizations over tar sands extraction, production, and transportation in Burnaby, British Columbia, Canada. Moreover, this work will elucidate the transformations of society-nature relationships brought by tar sands development. Research findings will provide scientific information about how the resistance movement in British Columbia can challenge the dominant narrative on tar sands, exert greater influence in environmental politics, and efficiently defend Indigenous people´s rights to lands. Furthermore, this research will shed light into how grassroots movements can contribute towards the building of more inclusive and sustainable societies.

Keywords: environmental conflict, environmental justice, extractive industry, indigenous communities, political ecology, tar sands

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Authors: Phuong Nguyen

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Along with the ongoing energy transition, the electrical power system is getting more vulnerable with the increasing penetration of renewable energy sources (RES). By replacing a large amount of fossil fuel-based power plants with RES, the rotating mass of the power grid is decreasing drastically, which has been reported by a number of system operators. This leads to a huge challenge for operators to secure the operation of their grids in all-time horizon ranges, from sub-seconds to minutes and even hours. There is a need to revise the grid capabilities in dealing with transient (angle) stability and voltage dynamics. While the traditional approaches relied on deterministic scenarios (worst-case scenarios), there is also a need to cover a whole range of probabilities regarding a wide range of uncertainties coming from massive RES units. To contribute to handle these issues, this paper aims to focus on developing a new analytical approach for transient stability.

Keywords: transient stability, uncertainties, renewable energy sources, analytical approach

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Authors: O. Lasaga

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Defining professional objectives and the search for work are some of the greatest stress factors for final year university students and recent graduates. To manage correctly the stress brought about by the uncertainty, confusion and frustration this process often generates, a course to control stress based on mindfulness has been designed and taught. This course provides tools based on relaxation, mindfulness and meditation that enable students to address personal and professional challenges in the transition to the job market, eliminating or easing the anxiety involved. The course is extremely practical and experiential, combining theory classes and practical classes of relaxation, meditation and mindfulness, group dynamics, reflection, application protocols and session integration. The evaluation of the courses highlighted on the one hand the high degree of satisfaction and, on the other, the usefulness for the students in becoming aware of stressful situations and how these affect them and learning new coping techniques that enable them to reach their goals more easily and with greater satisfaction and well-being.

Keywords: employability, meditation, mindfulness, relaxation techniques, stress

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Authors: Jose A. Romero, Frank Otremba, Alejandro A. Lozano-Guzman

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Road safety is affected by many factors, involving the vehicle, the infrastructure, and the environment. Many efforts have been thus made to improve road safety through rational standards for the different systems involved in freight transportation. Cargo shifting and falling have been recognized as critical and contributive effects for road crashes. To avoid such situations, regional and international standards have been implemented, aiming to prevent such types of cargo-related accidents. In particular, there are specific compulsory standard requirements to maintain the cargo on the vehicle without shifting, when the vehicle performs an emergency braking maneuver. In this paper, a simulation is presented to analyze the effect of the vibration of the cargo on the braking distance of the vehicle. Such vibration can lead to a poor cargo restraining, and higher braking efficiency, as a result of the decoupling of the cargo mass from the vehicle mass. Such higher braking efficiency, on the order of 4.4%, further suggests a greater demand for the current braking standards.

Keywords: road safety, cargo securement, shifting cargo, vehicle dynamics, ABS

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Authors: Hyung T. Kwak, Jun Gao, Yao An, Alfred Kleinhammes, Yue Wu

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Surface wettability is a crucial factor in oil recovery. In oil industry, the rock wettability involves the interplay between water, oil, and solid surface. Therefore, studying the interplay between adsorptions of water and hydrocarbon molecules on solid surface would be very informative for understanding rock wettability. Here we use the in-situ Nuclear Magnetic Resonance (NMR) gas isotherm technique to study competitive adsorptions of water and isopropanol, an intermediate step from hydrocarbons. This in-situ NMR technique obtains information on thermodynamic properties such as the isotherm, molecular dynamics via spin relaxation measurements, and adsorption kinetics such as how fast the system can reach thermal equilibrium after changes of vapor pressures. Using surfaces of silica glass beads, which can be modified from hydrophilic to hydrophobic, we obtained information on the influence of surface hydrophilicity on the state of surface water via obtained thermodynamic and dynamic properties.

Keywords: Wettability, NMR, Gas Isotherm, Hydrophilicity, adsorption

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Authors: Leonardo Herrera, Shield B. Lin, Stephen J. Montgomery-Smith, Ziraguen O. Williams

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A one-directional dynamic model of a Stewart Platform was developed to assist NASA in analyzing the dynamic response in spacecraft docking operations. A simplified mechanical drawing was created, capturing the physical structure's main features. A simplified schematic diagram was developed into a lumped mass model from the mechanical drawing. Three differential equations were derived according to the schematic diagram. A Simulink diagram was created using MATLAB to represent the three equations. System parameters, including spring constants and masses, are derived in detail from the physical system. The model can be used for further analysis via computer simulation in predicting dynamic response in its main docking direction, i.e., up-and-down motion.

Keywords: stewart platform, docking operation, spacecraft, spring constant

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Authors: Li Lu

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This work studies the processing of an all-solid-state sodium-ion battery (ASSB), utilizing sodium vanadium phosphate (NVP) as both the cathode and anode. The solid electrolyte is composed of a polymer matrix combined with nanoscale sodium zirconium phosphosilicate, Na₃Zr₂Si₂PO1₁₂ (NZSP) framework. To effectively enhance the desolvation of sodium salt, NaTFSI in the composite electrolyte, ferroelectric nano-ceramic particles are added to the electrolyte, achieving a high ionic conductivity in the range of 10⁻⁴ to 10⁻³ S/cm at room temperature. The full battery demonstrates impressive cycling performance, maintaining stability over 1000 charge/discharge cycles with minimal degradation. Atomic force microscopy (AFM) is employed to indirectly observe the ion transportation mechanisms within the battery, providing insights into the dynamics of sodium ion (Na⁺) movement. This study highlights the potential of polymer-NZSP composite electrolytes in enhancing the performance and longevity of ASSBs for next-generation energy storage applications.

Keywords: solid-state electrolyte, solid-state battery, composite electrolyte, impedance

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Authors: H. M. Ross-McAlpine

Abstract:

Much of what is written on diplomacy, globalization and the global economy addresses the changing nature of relationships between major powers. While the most dramatic and influential changes have resulted from these developing relationships the world is not, on deeper inspection, governed neatly by major powers. Due to advances in technology, the shifting balance of power and a changing geopolitical order, small states have the ability to exercise a greater influence than ever before. Increasingly interdependent and ever complex, our world is too delicate to be handled by a mighty few. The pressure of global change requires small states to adapt their diplomatic practices and diversify their strategic alliances and relationships. The nature and practice of diplomacy must be re-evaluated in light of the pressures resulting from globalization. This research examines: how small states can best secure their foreign policy objectives? Small state theory is used as a foundation for exploring the case study of New Zealand. The research draws on secondary sources to evaluate the existing theory in relation to modern practices of diplomacy. As New Zealand lacks the required economic and military power to play an active, influential role in international affairs what strategies are used to exert influence? Furthermore, New Zealand lies in a remote corner of the Pacific and is geographically isolated from its nearest neighbors how does this affect security and trade priorities? The findings note a significant shift since the 1970’s in New Zealand’s diplomatic relations. This shift is arguably a direct result of globalization, regionalism and a growing independence from the traditional bi-lateral relationships. The need to source predictable trade, investment and technology are an essential driving force for New Zealand’s diplomatic relations. A lack of hard power aligns New Zealand’s prosperity with a secure, rules-based international system that increases the likelihood of a stable and secure global order. New Zealand’s diplomacy and prosperity has been intrinsically reliant on its reputation. A vital component of New Zealand’s diplomacy is preserving a reputation for integrity and global responsibility. It is the use of this soft power that facilitates the influence that New Zealand enjoys on the world stage. To weave a comprehensive network of successful diplomatic relationships, New Zealand must maintain a reputation of international credibility. Globalization has substantially influenced the practice of diplomacy for New Zealand. The current world order places economic and military might in the hands of a few, subsequently requiring smaller states to use other means for securing their interests. There are clear strategies evident in New Zealand’s diplomacy practice that draw attention to how other smaller states might best secure their foreign policy objectives. While these findings are limited, as with all case study research, there is value in applying the findings to other small states struggling to secure their interests in the wake of rapid globalization.

Keywords: diplomacy, foreign policy, globalisation, small state

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Authors: Oliver Mărunţălu, Gheorghe Lăzăroiu, Elena Elisabeta Manea, Dana Andreya Bondrea, Lăcrămioara Diana Robescu

Abstract:

This paper presents the results obtained by numerical simulation of the pollutants dispersion in the atmosphere coming from the evacuation of combustion gases resulting from the fuel combustion used by electric thermal power plant using the software ANSYS CFX-CFD. The model uses the Navier-Stokes equation to simulate the dispersion of pollutants in the atmosphere. We considered as important factors in elaboration of simulation the atmospheric conditions (pressure, temperature, wind speed, wind direction), the exhaust velocity of the combustion gases, chimney height and the obstacles (buildings). Using the air quality monitoring stations we have measured the concentrations of main pollutants (SO2, NOx and PM). The pollutants were monitored over a period of 3 months, after that we calculated the average concentration, which is used by the software. The concentrations are: 8.915 μg/m3 (NOx), 9.587 μg/m3 (SO2) and 42 μg/m3 (PM). A comparison of test data with simulation results demonstrated that CFX was able to describe the dispersion of the pollutant as well the concentration of this pollutants in the atmosphere.

Keywords: air pollutants, computational fluid dynamics, dispersion, simulation

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