bluuebunny/crossref_metadata_2025 huggingface dataset:
CFD-DEM simulation of raceway size and mechanical characteristics of industrial scale blast furnace
Authors: Gao Yuzhen , Chan Choon Kit
Published: October 2023

The raceway plays a crucial role in ensuring the stable functioning of the ironmaking blast furnace. It is the key site where the chemical reaction of coke combustion takes place, providing the necessary heat and reducing gas for the upper iron ore reduction process. Consequently, the size of the raceway serves as an essential indicator of the blast furnace’s operational condition. In this study, a mathematical model for the raceway of an industrial-scale blast furnace was established. Extensive innovation investigations were conducted to explore the characteristics pertaining to the raceway’s size. The simulation outcomes demonstrate that both the particle size and the inlet velocity exert significant influences on the raceway dimensions. Specifically, the height of the raceway is predominantly affected by the particle size, whereas the inlet velocity predominantly influences the depth of the raceway.
Reverse Engineering-Inspired Parametric 3D Geometry Model of Marine Propeller
Authors: Zheng Long , Chen Shunhuai , Chen Xinyu , Ji Shengchen
Published: October 2023

In this study, an effective parametric 3D geometry model of a propeller was established with the aid of reverse engineering. The goal is to reduce the free parameters while automating the modelling of the propeller. The process of building the parametric model begins by generating an initial point cloud by defining the feature matrix associated with the propeller blade profile shape. Subsequently, the initial point cloud is deformed and refined by the deformation feature matrix and resampling. Finally, a 3D geometry model of the propeller is generated by surface reconstruction. The model can be built automatically by interactively modifying the feature matrices. Two numerical analyses illustrate the performance of the parametric 3D geometry model. Specifically, two propellers are constructed using the proposed model to estimate the shape error between the reconstructed propellers and the original offset of the propellers. These propellers are selected as research objects to determine the hydrodynamic performance error between the propeller constructed by the proposed model and a benchmark propeller. According to the results of the numerical study, the parametric 3D geometry model can precisely reconstruct the aforementioned geometry within a valid error range. The hydrodynamic error analysis demonstrates that the geometric inaccuracy from the reconstructed model has less impact on the propeller performance. This indicates that the model described in this study is generalised and robust. Moreover, some uncommon propeller CAD models were generated in batches using the parametric 3D geometry model.
Fault Diagnosis of Bearings Based on SSWT, Bayes Optimisation and CNN
Authors: Yan Guohua , Hu Yihuai , Shi Qingguo
Published: October 2023

Bearings are important components of rotating machinery and transmission systems, and are often damaged by wear, overload and shocks. Due to the low resolution of traditional time-frequency analysis for the diagnosis of bearing faults, a synchrosqueezed wavelet transform (SSWT) is proposed to improve the resolution. An improved convolutional neural network fault diagnosis model is proposed in this paper, and a Bayesian optimisation method is applied to automatically adjust the structure and hyperparameters of the model to improve the accuracy of bearing fault diagnosis. Experimental results from the accelerated life testing of bearings show that the proposed method is able to accurately identify various types of bearing fault and the different status of these faults under complex running conditions, while achieving very good generalisation ability.
Experimental Study of the Nonlinear Behaviour of Deep-Sea Mooring Polyester Fibre Ropes
Authors: Zhang He , Zeng Ji , Jin Bowen , Chou Chiate , Li Hangyu , Dong Hailei
Published: October 2023

Mooring ropes are essential components of ships and offshore floating structures and they are subjected to cyclic axial loads. This study investigates the evolution of the full-cycle stiffness of fibre polyester ropes under long-term static and dynamic loading. First, the static stiffness characteristics of the ropes, including the rope elongation properties at different stages, shrinkage rates, and creep coefficients after an idle period, are examined under static loads; an empirical formula for static stiffness is established. Second, the dynamic stiffness characteristics of the ropes are investigated under cyclic loads that are typical of platform production operations. The stabilities of the structure under different tensions are compared; the effects of mean tension, tension amplitude, and load cycle on the dynamic stiffness of the ropes are analysed and an empirical formula is established to predict the dynamic stiffness during the engineering design phase. The results of this study can be helpful for the rational design of deep-sea taut-leg mooring systems because they present the evolution of the full-cycle stiffness characteristics of mooring ropes.
Digitalization and smartening public governance of the European high north regions
Authors: DE MELO CARTAXO Tiago , HOSSAIN Kamrul
Published: October 2023

Balancing technological evolution, protection of the environment and social communities well-being has never been a simple task. However, while everything changes at an incredible fast-pace, public authorities, private entities and even civil society must accompany that movement. It is, therefore, crucial that primarily public officials and legislators build their activities on solid information, especially in places where a harsh climatic condition, sparse population distribution and longer distances make public involvement more difficult. The European high north is an example of a region where the recent phenomena of big data, certainly represents challenges because of its yet to fully developed infrastructure, but also opportunities for improving, peopleâ€™s lives, and enhancing sustainable development, through smart mechanisms. In fact, digitalisation and new technologies can cause negative and/or positive consequences in the life of certain communities, depending on the means and purposes they are used for. This article intends to demonstrate how an adaptive, in other words smart governance approach (digitalized governance approach) â€“ based on open, flexible and participatory tools â€“ could improve the life of human beings in the territories of the European High North (EHN), preparing the  region and its inhabitants for the challenges of sustainable development.
Hofstede`s model in the context of e-government and open government in EU countries: countries clustering based on similarities and differences
Authors: NIKOLOV Hari Stankov , KRUMOVA Milena Yordanova
Published: October 2023

This research tries to answer the question â€œHow does the Hofstede`s Model of societal cultural differences relate to the development of EU countries e-government and open government?â€. This question of interest in the research comes from the growing number of discussions about how the culture impacts the economic growth, but much more because of the literature GAP about the factors of relations among the Hofstede`s Model dimensions and the new governance models in the EU countries. Based on a literature overview and analyze we propose a thesis is that the analyzed EU countries can be clustered into three. The countries, which fall into the same cluster entitled Cluster of Changers, possess cultural similarities and this relates to the progressive development of the open and e-government. This is such because these countries possess the same characteristics defined by the Hofstede`s model. The second cluster of countries, we entitled them Cluster of Observers, are characterized by similar characteristics according to Hofstede`s model, they have slow development in the open and e-government. And the third one, the cluster Cluster of Moderators falls neither into the cluster of Changers or Observers. We propose a matrix model, which explains the Hofstede`s model of cultural dimensions in regards to the e-government development and open government of the EU countries.
The role of smart cities to promote smart governance in municipalities
Authors: LANGA Vuyani Goodman , THAKHATHI Reckson Dovhani
Published: October 2023

The main focus of this paper is to provide a contextualized reflection about what smart cities are and their primary contribution in promoting smart governance.

Objectives

Objectives include amongst others, the definition of the smart city concept and how it can be used as a means to achieve more efficient and sustainable cities. It further elucidates the use of internet enhanced public service delivery to promote smart governance in municipalities.

Prior Work

This paper is built upon existing prior work that has been done in the emerging trends in smart cities. Researchers have identified several different “discourses” related to smart cities However, this paper delves deeper into how innovation and the concept of internet of things can enhance public service delivery. It further contextualizes the use of internet enabled public services with the purpose of making municipalities smart cities, with smart governance by offering smart services to its communities.

Approach

A qualitative research approach was used to fulfil the objectives of the paper through an in-depth desktop analysis of existing literature from recent journals.

Results

The research findings traverse that although a plethora of challenges remain, it is the amenability of both the political and administrative leadership and the gravity attached to technology that determines the extent of depth of transforming municipalities towards the goal of being smart cities.

Implications

The overall goal of this paper is to lay a foundation for the development of a comprehensive framework to redirect administrators and political office bearers towards smart city and smart governance inclined policy directives as suggested in the research findings. Inferences drawn from the paper will assist in further research in the field of innovation, smart cities and smart governance as wheels and machinery of service delivery.

Value

Finally, this paper attempts to merge theory and practice to work towards understanding of what a smart city means for South African cities through smart governance manage and minimize challenges confronted by municipalities through the use of technology.
A Cellular Automaton-Based Technique for Estimating Mineral Resources
Authors:   Department of Mining Engineering Kazi Nazrul University, Asansol West Bengal, India, Paty Soumyadeep , Kamilya Supreeti ,   Department of Computer Science and Engineering BIT Mesra, Ranchi Jharkhand, India
Published: October 2023

A significant contribution to the economic growth of a nation comes from the mineral industries. Therefore, the concentration of metallic or nonmetallic minerals in different regions of Earth’s crust is important to determine. The present paper studies the grade and thickness estimation of iron and coal deposits, respectively, by applying two-dimensional cellular automata (CAs). Krigging is a popular method for the estimation of mineral resources. However, krigging results in complex mathematical calculations if the number of sample points increases. Here, each cell of the cellular automaton (CA) is represented as a block. Using CAs, the grade values and thickness are estimated in a simpler and faster way. Two-dimensional CAs are used in this paper where the local rule is the ordinary krigging estimator function using the spherical variogram model. The total weight of iron as well as coal is calculated using the CA-based technique. A comparative analysis between the estimated weight of minerals and the actual extracted mineral is also given.
One-Dimensional Cellular Automaton Transitions and Integral Value Transformations Representing Deoxyribonucleic Acid Sequence Evolutions
Authors:   Electronics and Communications Sciences Unit, Indian Statistical Institute Kolkata-700108, India, Ghosh Sreeya , Sahoo Sudhakar ,   Institute of Mathematics and Applications Bhubaneshwar-751029, India, Hassan Sk. Sarif ,   Department of Mathematics, Pingla Thana Mahavidyalaya Paschim Medinipur-721140, India, Das Jayanta Kumar ,   School of Medicine, Johns Hopkins University MD-21287, USA Applied Statistics Unit, Indian Statistical Institute Kolkata-700108, India, Choudhury Pabitra Pal ,   Applied Statistics Unit, Indian Statistical Institute Kolkata-700108, India, Sengupta Antara ,   Department of Computer Science and Engineering, University of Calcutta Kolkata-700009, India
Published: October 2023

The cellular automaton (CA) and an integral value transformation (IVT) evolving in discrete time steps are two mathematical models that are well established. Theoretically, it can be suggested that a CA possesses the capacity to produce varieties of evolutionary patterns. However, computing a CA in higher dimensions or computing a nonlinear CA may be complex. In such cases, an IVT can be conveniently used. This paper presents the relation between the transition functions of a one-dimensional CA and an IVT. It also highlights the algebraic structures on the basis of binary operations for a set of transition functions of a one-dimensional CA and for a set of IVTs. The suitability of using an IVT over a CA is discussed. Also, we present the evolutionary models of two deoxyribonucleic acid (DNA) sequences through IVTs and their spacetime diagrams. This can eventually bring out some characteristic features of the evolutionary sequences.
Special Issue: Selected Papers from the First Asian Symposium on Cellular Automata Technology, 2022 (ASCAT 2022)
Authors:   Department of Information Technology, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, West Bengal, India, Das Sukanta , Martínez Genaro J. ,   School of Computer Sciences, National Polytechnic Institute, Mexico City, Mexico
Published: October 2023

This special issue contains six papers that are the extended versions of six selected contributions that were presented at the First Asian Symposium on Cellular Automata Technology, 2022 (ASCAT 2022). The symposium was officially organized by the departments of Information Technology and Computer Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur (IIEST, Shibpur), India, March 3–5, 2022, in online mode. Cellular Automata India (https://www.cellularautomata.in) is an open research group that was created during the pandemic period by a group of Indian researchers and took a leading role in organizing the event. There are a number of international conferences and workshops that consider cellular automata as the primary theme and deal with various aspects of cellular automata and their theoretical, modeling and application development issues. Since the late 1980s, cellular automata have been used to devise solutions for technological problems, particularly in the domain of very large-scale integration (VLSI) design and test, pattern recognition and classification, security and image processing. The aim of this symposium was to focus on the issue of technology development by cellular automata. In our view, ASCAT was the first event of this kind. Since technology cannot mature without a solid theoretical base, this symposium invited theoreticians and engineers to exchange their views and ideas. In this symposium, 14 papers were selected for presentation. We invited all the authors of the 14 papers to submit extended versions of their works for inclusion in the planned special issue. The submitted extended versions were reviewed again and finally six papers were chosen for this special issue. We thank all the authors of this issue for their efforts to beautifully extend their research. We are very greatly thankful to the reviewers who gave their efforts to review the papers and to select these six papers. We hope that these papers will be a good contribution to the field of cellular automata.
Deuda técnica en arquitectura: una estrategia de identificación
Authors: Pérez Boris
Published: October 2023

La deuda técnica en arquitectura es una metáfora de las decisiones tomadas por los arquitectos para alcanzar objetivos a corto plazo, pero que pueden dañar la salud del sistema a largo plazo. Esta deuda técnica es difícil de detectar, ya que está asociada a la mantenibilidad y la evolución a largo plazo de un sistema. En esta investigación, describimos un método basado en la evolución de la arquitectura para la identificación de la deuda que está respaldado por un modelo de aprendizaje automático supervisado y se basa en la información obtenida de los artefactos producidos durante el diseño de la arquitectura. Descubrimos que, incluso con una pequeña cantidad de datos, el modelo de aprendizaje automático produce buenos resultados en términos de Recall e incluso de Accuracy. Las experimentaciones realizadas proporcionaron información que nos permite concluir que esta idea funciona bien y podría utilizarse como punto de partida para ayudar a los arquitectos a identificar y gestionar la deuda técnica en arquitectura
"The council was a conflict commission, not a governing body".Activities of the Council of Curators of Suburban Palaces and Museums.
Authors: Bondarev Sergei Viktorovich
Published: October 2023

The subject of the study is the Council of Curators of Suburban Palace Museums. In mid-1918, under the People's Commissariat of Education, the Council of Suburban Leaders was created in order to consolidate efforts to transform the royal residences into museums. The guardians of Peterhof, Tsarskoe Selo, Gatchina, and Pavlovsk palaces decided at meetings numerous issues regarding the future of the royal palaces. The author examines in detail such aspects as the problems of the daily activities of the suburbs, reforms in the management of palace-museums. Particular attention is paid to the following areas of the Council's activities: the authorities' claims to the property of former residences, personnel issues, problems of financing, security, etc. The methodological basis of the study is the principles of historicism, objectivism and systematic scientific analysis. The main conclusion of the study is the determining role of the Council in relation to state policy to create a unified management body for palaces and museums. The Council was a platform for expressing the public position of representatives of the intelligentsia. The curators openly discussed with cultural officials about the future structure of the palace-museums. The novelty of the study lies in the fact that for the first time an attempt has been made to analyze the activities of the Council of Curators of Suburban Palaces and Museums. Despite the lack of authority to make independent decisions, the Council was able to prove to the authorities the need to separate palace-museums into a separate group of art-historical organizations. And also achieve the creation of a separate government body to centralize the management of the suburbs.
Investigating Speech Acts In Selected Dialogues Concerning Multicultural Values In the Indonesian Ministry of Educational & Culture- Endorsed High School Textbook: A Discourse Analysis
Authors: Masturoh Siti , Said Iskhak , Rohayati Dedeh
Published: October 2023

This paper is a discourse analysis that aims at investigating speech acts in a selected dialogue about multicultural values in the Indonesian Ministry of Educational & Culture-endorsed high school EFL textbook (twelfth grade). Speech acts theory was employed in processing the analysis of dialogues. The intended features were recognized, categorized, identified separately, and analyzed based on five major speech acts developed by Searle (1976). The findings revealed that 51% of utterances includes in the assertive category, the expressive category is 29%, while the directive and commissive categories have the same results (10%), and the declarative category does not have any outcome (0%). In addition, the presentation of the multicultural value in the Indonesian Ministry of Educational and Culture-Endorsed High School EFL Textbook (twelfth grade) 2018 revision through dialogue has proved to lack key. Based on this finding, it is recommended to investigate how the multicultural values are presented in the newest edition of textbooks and to cultivate the multicultural values using another methodology or the future researchers can use gender as the subject of the study.
Evolving Roles of Public Health Nurses in the Age of Pandemics: A Rapid Review
Authors: Sharkiya Samer
Published: October 2023

Background: Public health nurses are essential in reacting to and controlling pandemics. Their responsibilities have changed as the globe faces more intricate health issues relating to newly developing infectious illnesses. This literature review aims to identify suggestions to enhance public health nurses' practice and offer a thorough knowledge of the changing responsibilities of public health nurses in the era of pandemics.

Methods: The important themes, difficulties, and possibilities connected to public health nursing during pandemics were highlighted after relevant papers were found through a thorough search of databases.

Conclusion: Public health nurses play a vital role in combating new infectious illnesses, utilising technology, bolstering health systems, fostering interprofessional teamwork, advocating for health equality, engaging communities, and supporting mental health and wellbeing. However, they deal with serious issues such as a lack of skilled labour, poor funding, and quickly advancing knowledge. Enhancing workforce planning and development, bolstering public health infrastructure, creating and disseminating evidence-based guidelines and protocols, encouraging interprofessional collaboration and education, addressing health disparities and promoting health equity, and supporting continuous learning and professional development are all recommendations for improving pandemic preparedness and response.
Prediksi Toksisitas In Silico Senyawa Bioaktif Daun Kemangi (Ocimum sanctum. L)
Authors: Wangsasaputra Ester , Prihandini Satria , Ginting Chrismis Novalinda , Chiuman Linda
Published: October 2023

Pendahuluan: Ocimum sanctum L. (daun kemangi) banyak ditemukan dan sering digunakan sebagai bahan makanan di Indonesia. Senyawa flavonoid merupakan kelompok senyawa kimia yang banyak terkandung dalam Ocimum sanctum L. Senyawa ini dikenal dengan aktivitas biologisnya yang beragam, antara lain antibakteri, antimikroba, antiinflamasi, antimalaria, dan antikanker. Pada penelitian ini, kami bertujuan untuk menyelidiki penyerapan, distribusi, metabolisme, ekskresi, dan toksisitas (the absorption, distribution, metabolism, excretion, and toxicity/ADMET) senyawa flavonoid dalam Ocimum sanctum L.

Metode: Dalam mencapai tujuan penelitian, prediksi properti ADMET senyawa flavonoid pada Ocimum sanctum L. dilakukan menggunakan tiga web server yang terdiri dari SwissADME, pkCSM, dan ProTox-II. Parameter yang diamati dibagi menjadi parameter ADMET.

Hasil: Hasil penelitian menunjukkan bahwa senyawa flavonoid dalam Ocimum sanctum L. memiliki median lethal dose (LD50) yang berkisar antara 2000 mg/kg hingga 5600 mg/kg, dengan klasifikasi kelas toksisitas IV, V, dan VI. Selain itu, senyawa flavonoid ini menunjukkan imunotoksisitas, sitotoksisitas, dan dampak pada Mitochondrial Membrane Potential (MMP).

Kesimpulan: Penelitian kami menunjukkan bahwa senyawa metabolik yang berasal dari Ocimum sanctum L. dianggap aman.
Analisis Strategi CSR Bank Indonesia dalam Membangun Hubungan Komunitas
Authors: Sutarto Joan , Natalia El Chris
Published: October 2023

Corporate Social Responsibility (CSR) is an effort to improve society or communities’ welfare in corporate business operations area. One of the problems in Indonesia is in education, this caused Bank Indonesia to contribute in overcoming the problems through scholarship program and Bank Indonesia scholarships recipients community establishment called New Generation of Indonesia (GenBI). This study aimed to comprehend Bank Indonesia CSR strategy in building community relations. CSR strategy was analyzed by CSR Hierarchy and Triple Bottom Line, while community relations was analyzed by Community Relations Elements and the development and success factors of community relations. This study used a qualitative-descriptive approach with interviews, observation, and document studies as data collection techniques. The results showed Bank Indonesia's CSR strategy was divided into two inseparable programs, and there were efforts to build community relationships. However, communication still needs to be improved, such as through offline meetings to build and strengthen community relations.
LOW NOX BURNERS FOR POWER BOILERS
Authors:   Omsk State Technical University, Omsk, Russia, Batrakov P. A. , Tsikhler M. V. ,   Omsk State Technical University, Omsk, Russia
Published: October 2023

The article discusses the rationality of using burners with low NOx emissions and processes that limit their formation. Low NOx burners are the most efficient solution to the problem of NOx formation. The task is to satisfy the conditions: temperature, mixing of fuel with an oxidizer, determined by the most favorable reaction paths and the kinetics of mutual transformations of nitrogen compounds in a flame. The use of burners with low NOx emissions in various industries, especially in the energy sector, is an urgent task.
STUDY OF THE DISTRIBUTION OF POWER FLOWS IN AN ELECTRICAL SYSTEM WITH A SOLAR POWER PLANT AND LOAD
Authors:   Omsk State Technical University, Omsk, Russia, Andreeva E. G. , Kosarev B. A. ,   Omsk State Technical University, Omsk, Russia, Fedorov V. K. ,   Omsk State Technical University, Omsk, Russia, Khamitov R. N. ,   Omsk State Technical University, Omsk, Russia, Okhotnikov A. A. ,   Omsk State Technical University, Omsk, Russia, Koshchuk G. A. ,   Omsk State Technical University, Omsk, Russia
Published: October 2023

Implementation of distributed energy resources based on renewable energy sources in existing electrical systems leads to a change in the direction and magnitude of power flows and, as a result, to a change inthe parameters of the network operation mode. The aim of the work is to study power flows in power supply systems with distributed generation facilities. To achieve this goal, power flows in the electrical system with thepower supply system, solar power plant, battery and load are analyzed. The results of the experiments showed that at the power supply point of the load of the electrical system, a low value of the power factor and the occurrence of a reactive power flow into the power system are observed. The results obtained on the value of the power factor in the electrical system with a solar power plant, can be used for further research and in practice.
FREQUENCY MEASUREMENT METHOD BY THREE SAMPLES OF THE INPUT SIGNAL
Authors:   National Research University ", Evtekhova D. S. ,   Moscow Power Engineering Institute",   , Moscow, Russia, Serov A. N. ,   National Research University "Moscow Power Engineering Institute", Moscow, Russia
Published: October 2023

The paper deals with the method of signal frequency measurement based on the analysis of three consecutive samples of the input signal. The ad-vantages and disadvantages of the method are considered. The method of error re-duction, based on the use of a low-frequency filter, is proposed. The simulation model is built with the help of Simulink package. An estimate of the error for the case of sinusoidal, polyharmonic and sinusoidal distorted by noise signals is obtained.
ANALYSIS OF SIMULATION RESULTS FOR A LOW-POWER SYNCHRONOUS MOTOR WITH PERMANENT MAGNETS TAKING INTO ACCOUNT THE MAGNETIC PROPERTIES ABOUT THE STEEL OF THE MAGNETIC SYSTEM
Authors:   Omsk State Technical University, Omsk, Russia, Andreeva E. G. , Tatevosyan A. S. ,   Omsk State Technical University, Omsk, Russia, Tereschenko N. A. ,   Omsk State Technical University, Omsk, Russia
Published: October 2023

The article discusses the issues of modeling a linear and nonlinear electrodynamic problems for calculating the unsteady magnetic field of a synchronous motor with permanent magnets (SMPM) of low power, for clarifying the determination of the parameters of its stator winding, when the analyzing transient and emergency modes of operation the motor. The results of computational experiments are presented. Calculations were carried out in the software package Elcut (professional). The influence of the use of nonlinear magnetic characteristics of magnetic core steel (magnetization curve) in the software package on the resistance of the motor armature (stator) winding has been evaluated. Recommendations were received to refine the simulation model of the next stage of the design of the SDPM.
SIMULATION OF A CAPACITIVE SENSOR FOR PD REGISTRATION IN POWER CABLE
Authors:   Omsk State Technical University, Omsk, Russia, Polyakov D. A. , Romantsova S. A. ,   Omsk State Technical University, Omsk, Russia
Published: October 2023

The article discusses the simulation of a partial discharge (PD) pulse in a power single-core coaxial cable using a capacitive sensor. The sensor provides capacitive coupling to the test sample and its capacitive element is in fact part of the total capacitance of the cable. The resistive element added to the design makes it possible to register current pulses of partial discharges. At the same time, the used sensor has no connection with high-voltage electrodes of the systems, which is its undoubted advantage in comparison with conventional capacitive sensors.
EXPERIMENTAL STUDY OF THE WINDING INDUCTANCE OF A SLOW-SPEED SYNCHRONOUS MAGNETO-ELECTRIC MOTOR AS A PART OF A SINGLE-STAGE RECIPROCATING COMPRESSOR DRIVE
Authors:   Omsk State Technical University, Omsk, Russia, Tatevosyan A. A. , Segrenev M. V. ,   Omsk State Technical University, Omsk, Russia, Smorodin G. S. ,   Omsk State Technical University, Omsk, Russia
Published: October 2023

The article presents an experimental study of the winding inductance of a model sample of a low-speed synchronous motor with permanent magnets (SMPM) as part of a reciprocating drive of a long-stroke reciprocating compressor. The design of the developed one implies the use of eight coils, and the smallest losses in the windings are observed when the coils are turned off, which are outside the zone of permanent magnets during the reciprocating motion of the inductor. Switching windings is accompanied by a voltage pulse, which negatively affects the operation of solid state relays. Thus, the task of experimental study of the inductance of coils and measures to reduce its influence during switching is an urgent task.
Estimation of the reference value of pubofemoral distance in normal infants by ultrasonography: A pilot study in Indian population
Authors: Chawla Siddhi , Meena Gaurav
Published: October 2023

Objectives:

The objectives of this study were to determine the normal values of pubofemoral distance (PFD) and its variation with age, sex, and laterality of hip in infants in the Indian population.

Material and Methods:

The PFD was measured in 141 infants falling under Grafs categories I, IIa, and IIb (Males: 77 and Females: 64) divided into two groups comprising the neonatal group (<1 month) and postneonatal group (>1–12 months). PFD measurement and Grafs’ method of alpha- and beta-angle measurement were both performed at the same time by doing an ultrasound of the hip. Probe was placed in the coronal plane in lateral decubitus with the flexed position in a neutral position. PFD was measured between the superior pubic rami and femoral head epiphyses.

Results:

The average PFD in 141 infants (282 hips) was 3.23 ± 0.83 mm. It was 3.15 ± 0.79 mm in the neonatal group (88 patients) and 3.47 ± 0.84 mm in the postneonatal group (53 patients). In males, the average PFD was 3.29 ± 0.85 mm, and in females, it was 3.23 ± 0.81 mm. No significant difference was observed in the average PFD among the two sexes and between the left and right hips of both neonatal and postneonatal groups.

Conclusion:

The study demonstrates reference PFD values in infants aged 0–12 months in neonatal and postneonatal age groups. Mean PFD values were not significantly influenced by the laterality or sex of the patient in both groups, however, increased with age. Further studies need to be done however to find its values in the cases with developmental dysplasia of the hip to determine the cutoff in such cases.
How poisoning is avoided in a step of relevance to the Haber-Bosch catalysis
Authors: Tripathi Shivam , Bonati Luigi , Perego Simone , Parrinello Michele
Published: October 2023

For a catalyst to be efficient and durable, it is crucial that the reaction products do not poison the catalyst. In the case of the Haber-Bosch iron based catalyst, the rate-limiting step is believed to be the decomposition of nitrogen molecules on the Fe(111) surface. This step leads to the production of atomic nitrogen on the surface N* that unless are hydrogenated and eventually released as NH3 molecules, remain on the surface. Thus, it is important to ascertain how a high N* coverage affects nitrogen dissociative chemisorption. To answer this question, we study the properties of the Fe(111) surface at different N* coverage both at room and operando temperature. Using state-of-the-art simulations, we have already found that, at high temperatures, the surface atoms are highly mobile and that the catalytic centers normally associated with the surface activity acquire a finite lifetime [1]. Here, we discover that the N* surface atoms are highly mobile and that coverage reduces but does not eliminate iron mobility. The N* atoms promote the formation of metastable iron triangular surface structures whose chemical composition can be described as F e_3^*N_i^* i = 1, 4. These structures are the result of the frustrated drive of the system towards a more stable Fe4N phase. As a consequence of the formation of these structures, nitrogen atoms tend to cluster, reducing their poisoning effect. At the same time, the reduction in the number of catalytic centers is counteracted by an increase in their lifetime. The combined effect is that the barrier for dissociation is not significantly altered at least up to the maximum coverage studied here of 50%.
Evaluating development of empirical estimates using two top-down methods at midstream natural gas facilities
Authors: Brown Jenna , Harrison Matthew , Rufael Tecle , Roman-White Selina , Ross Gregory , George Fiji , Zimmerle Daniel
Published: October 2023

To align with climate initiatives, multiple reporting programs are transitioning from generic activity-based emission factors to site-specific measured emissions data to estimate greenhouse gas emissions at oil and gas facilities. This study contemporaneously deployed two top-down (TD) aerial methods across 14 midstream facilities, extending work done in Brown et al.1. Methods produced multiple whole-facility estimates at each facility, resulting in 773 individual paired estimates (same facility, same day), and robust mean estimates for each facility. Mean estimates for each facility, aggregated across all facilities, differed by nearly 2:1 (49% [32% to 68%]). At 6 of 14 facilities, the methods produced mean estimates that differed by more than a factor of two. These data suggest that one or both methods did not produce accurate facility-level estimates, at a majority of facilities and in aggregate across all facilities. Overall results are augmented with two case studies where TD estimates at two pre-selected facilities were coupled with comprehensive onsite measurements to understand factors driving the divergence between TD and bottom-up (BU) emissions estimates. In 3 of 4 paired comparisons between the intensive onsite estimates and one of the TD methods, the intensive onsite surveys did not conclusively diagnose the difference in estimates. In these cases, our work suggests that the TD methods mis-estimate emissions an unknown fraction of the time, for unknown reasons. While two methods were selected for this study, it is unlikely that the issues identified here are confined to these two methods; similar issues may exist for other similar whole-facility methods, on midstream and/or other facility types. These findings have important implications for the construction of voluntary and regulatory reporting programs that rely on emission estimates for reporting, fees or penalties, or for studies using whole-facility estimates to aggregate TD emissions to basin or regional estimates.
Benchmarking the MBE, FMO, and CPF GPU-Accelerated Fragmentation Methods for Accuracy and Parallel Time-to-Solution
Authors: Kazemian Fazeleh , Galvez Vallejo Jorge , Gilbert Andrew , Seeger Zoe , Izgorodina Ekaterina , Barca Giuseppe Maria Junior
Published: October 2023

We present an accuracy analysis of several fragmenta- tion methods including the embedding-free Many Body Expansion (MBE), the electrostatically-embedded MBE (EE-MBE), the Fragment Molecular Orbital (FMO) and the presently introduced Coulomb Per- turbed Fragmentation (CPF) method. We show that the iterative correction to the electrostatic potential in FMO introduces little to no accuracy gains when com- pared to the non-iterative EE-MBE and CPF methods. Additionally, we present performance comparisons of GPU accelerated implementations of most of these methods and show that MBE4 is not only more ac- curate than FMO3 but, when sufficient parallelism is provided, it is also faster.
Fuel Cells - An Overview of Their Green Value and Readiness Levels
Authors: Adeyanju Adedayo
Published: October 2023

With CO2, nitrous oxides, and methane emissions data across the African continent, this review paper quantitatively describes the health, environmental, and mortality (expressed as avoidable deaths in thousands per year) effects that the combustion of fossil fuels generates. As a solution, this research study goes further to describe, with visual aids, the technology of fuel cells, their attractive green value, the types of fuel cells including low-temperature and high-temperature fuel cells (LTFC & HTFC) that enable different applications, as well as their levels of commercialization readiness.
A Supported Ziegler-Type Organohafnium Site Metabolizes Polypropyl-ene
Authors: Samudrala Kavyasripriya , Conley Matthew
Published: October 2023

Cp2Hf(CH3)2 reacts with silica containing strong aluminum Lewis acid sites to form Cp2Hf–13CH3+ paired to aluminate ani-ons. Solid-state NMR characterization shows that this reaction also forms neutral organohafnium and hafnium sites lacking methyl groups. Cp2Hf–13CH3+ reacts with isotatic polypropylene (iPP, Mn = 13.3 kDa; Đ = 2.4; mmmm = 94 %; ~110 C3H6/Hf) in the presence of H2 to form oils with moderate molecular weights (Mn = 290 - 1200 Da) in good yields. The ali-phatic oils show characteristic 13C{1H} NMR properties consistent with complete loss of diastereoselectivity and formation of regioirregular errors under 1 atm H2. These results show that a typical Ziegler-Natta type active site is compatible in a common reaction used to digest waste plastic into smaller aliphatic fragments.
A fluorescence approach for an online measurement technique of atmospheric microplastics
Authors: Gratzl Jürgen , Seifried Teresa M. , Stolzenburg Dominik , Grothe Hinrich
Published: October 2023

Microplastic particles in the atmosphere are regularly detected in urban areas as well as in very remote locations. Yet the sources, chemical transformation, transport, and abundance of airborne microplastics still remains largely unexplained. Therefore, their impact on health, weather and climate related processes lacks comprehensive understanding. Single particle detection presents a substantial challenge due to its time-consuming process and is conducted solely offline. To get more information about the distribution, fluxes and sources of microplastics in the atmosphere, a reliable and fast online measurement technique is of utmost importance. Here we demonstrate the use of autofluorescence of microplastic particles for their online detection with a high sensitivity towards different widely used polymers. We deploy online single particle fluorescence spectroscopy with a Wideband Integrated Bioaerosol Sensor WIBS 5/NEO (Droplet Measurement Technologies), which enables single particle fluorescence measurements at two excitation wavelengths (280 nm and 370 nm) and in two emission windows (310 – 400 nm and 420 – 650 nm). We investigated shredded (< 100 μm) everyday plastic products (drinking bottles, yogurt cups) and purchased pure powders of polyethylene terephthalate (PET), polyethylene (PE) and polypropylene (PP). For that broad range of typical plastic products analyzed, we detected fluorescence on a single particle level using the WIBS. The online detection is possible even for particles smaller than 2 μm, with a remarkable detection efficiency of microplastic particles from a PET bottle as small as 1.2 μm with 95% effectivity. Comparison with biological aerosol reveals that microplastics can be distinguished from two abundant pollen species and investigation of the complete fluorescence excitation emission maps of all samples show that online identification of microplastics might be possible with fluorescence techniques if multiple channels are available.
A High Efficiency Gas Phase Photoreactor for Eradication of Methane from Low-Concentration Sources
Authors: Krogsbøll Morten , Russell Hugo S. , Johnson Matthew S.
Published: October 2023

Despite the urgent need, very few methods are able to efficiently remove methane from waste air with low cost and energy per unit volume, especially at the low concentrations found in emissions from e.g. wastewater treatment, livestock production, biogas production and mine ventilation. We present the first results of a novel method based on using chlorine atoms in the gas phase, thereby achieving high efficiency. A laboratory prototype of the Methane Eradication Photochemical System (MEPS) technology achieves 58% removal efficiency with a flow capacity of 30 L/min; a reactor volume of 90 L; UV power input at 368 nm of 110 W; chlorine concentration of 99 ppm; and a methane concentration of 55 ppm; under these conditions the apparent quantum yield (AQY) ranged from 0.48 to 0.56% and the volumetric energy consumption ranged from 36 to 244 kJ/m3. The maximum achieved AQY with this system was 0.83%. A series of steps that can be taken to further improve performance are described. These metrics show that MEPS has the potential to be a viable method for eliminating low-concentration methane from waste air.
Diverse Metastable Diarylacetonitrile Radicals Generated by Polymer Mechanochemistry
Authors: Yamamoto Takumi , Aoki Daisuke , Mikami Koichiro , Otsuka Hideyuki
Published: October 2023

Fluorescent radicals have attracted great attention as luminescent materials, mostly on account of their potential to achieve higher luminescence efficiency than closed-shell molecules. However, analyzing fluorescent radicals at ambient conditions remains a challenging task, because radicals are usually unstable in air. In addition, to the best of our knowledge, research aimed at controlling fluorescence wavelengths through substituent changes has not yet been accomplished. Here, we report diverse metastable diarylacetonitrile (DAAN) radicals, which contain different substituents, generated by polymeric mechanochemical reactions. The DAAN radicals, generated by ball-milling powdered polystyrene together with DAAN derivatives, were dispersed within the polystyrene matrix, where they retained their radical state, which allowed measuring solid-state fluorescence spectra. These measurements revealed that a wide range of fluorescence wavelengths from green to red (λem,max = 517–635 nm) can be achieved only by changing the substituents on the aromatic rings in these DAAN radicals. This phenomenon has not been observed for the well-studied triarylmethyl radicals. The fluorescence wavelength of these DAAN radicals can be precisely estimated by time-dependent density-functional theory (TD-DFT) calculations. The amount of DAAN radicals generated upon ball-milling is discussed in conjunction with DFT calculations and experimental results. Our results suggest that the orbital interactions with polymeric mechanoradicals, the bond-dissociation enthalpy, and the steric protection of the radical center are of paramount importance for the generation of DAAN radicals. The results of this study can be expected to provide useful guidelines for the development of advanced fluorescent radicals.
Mechanistic study of the atomic layer deposition of cobalt: A combined mass spectrometric and computational approach
Authors: Donnecke Sofia , Paul Mathias , Chan Serena , Tse Veronica , Sachdeva Jigyasa , Williams Peter , Paci Irina , McIndoe J. Scott
Published: October 2023

Cobaltcarbonyl-tert-butylacetylene (CCTBA) is a conventional precursor for the selective atomic layer deposition of Co onto silica surfaces. However, the limited understanding of the deposition mechanism of such cobalt precursors curbs rational improvements on their design for increased efficiency and tuneable selectivity. The impact of using a less reactive internal alkyne to a terminal alkyne was investigated using experimental and computational methods. Electrospray-ionization mass spectrometry was used to monitor the formation of CCTBA analogs and study their gas phase decomposition pathways. Gas phase analysis show that an internal alkyne dissociates at slightly lower energies than a terminal alkyne, suggesting that an internal alkynyl ligand may be more suited to low temperature ALD. Furthermore, the less reactive internal alkyne will result in fewer carbon impurities embedded in surfaces, in particular due to its reduced reactivity with Si-H bonds on the surface of Si wafers. Computational analysis also predicts increased surface binding in the metal centers of the internal alkynyl complex.
Methods of theaching geography in profile 10th grades
Authors: Shynkarenko Hanna , Zhemerov Alexander
Published: October 2023

Introduction. The study of geography in modern conditions is very important for the development of youth and the nation as a whole. There is a growing need in the society to study geographical science at a level higher than the standard one. At present, there is an opportunity to study geography in senior classes in depth at the profile level.

The purpose of this article is to highlight the methods of teaching geography for students of specialized 10th grade.

Main material. The authors consider the method of teaching profile level geography for 10th grade students. The article analyzes curriculum, the main tasks and nature of geography study, singles out directions of practical activity in different kinds of work, as well as the teacher’s work in different employment conditions.

Practical activities for the 10th grades of the profile level have a fairly large workload in hours, so most work should be done independently to demonstrate the results and knowledge to the teacher and the class.

During the study, the authors made a list of requirements for the study of geography, including approaches, types, technologies, methods of teaching students. The article analyzes practical works on the course of profile geography in the 10th grade and the main forms of conducting lessons during the study.

Conclusions. The curriculum in geography is aimed at developing students in various fields. Teachers need to adapt quickly to the latest conditions in teaching geography and help students learn about the world. The curriculum of the profile level for the 10th grade contains a rather large workload for geography teachers and students, so it is aimed at effective study of the course and a large amount of work done. The basic requirements for the study of geography, levels of mental activity, types of learning and different methods of cognitive activity in teaching geography were analyzed in the course of study. During the analysis of two practical works, the authors have singled out basic knowledge and skills that students consolidate and develop during the task. Each student develops research skills and the ability to achieve the expected result while completing the task.