bluuebunny/crossref_metadata_2025 huggingface dataset:
Legal Certainty Of Trademark Registration To Improve The Welfare Of Micro, Small And Medium Enterprises (Msmes)
Authors: Saka Risti , Santiago Faisal
Published: November 2024

Micro, Small and Medium Enterprises (MSMEs) hold role important in the Indonesian economy, but they often face challenge in protect asset intellectual, especially brand. Uncertainty law in registration brand cause risk piracy and its impact negative on power competition as well as sustainability UMKM business. Research This aiming For explore certainty law in registration brand for MSMEs in Indonesia and evaluate the impact to welfare economy UMKM actors. Research This use approach law empirical, conducted in several city with high UMKM population, Data collection techniques were carried out with method survey and observation field, and semi- structured interview. Research results show that although registration brand give protection significant for MSMEs and improve Power competition they, still there is constraint in accessibility, understanding law, and costs. Implications from study This underline importance role government in give education, simplifying the registration process, and providing support financial for MSMEs. With existence more policies? inclusive, MSMEs are expected can protect brand they in a way effective, which ultimately strengthen economy local and national.
Legal Implications Of Ai-Assisted Medical Waste Management In Healthcare Facilities
Authors: Sebastian Rommy
Published: November 2024

Medical waste management in healthcare facilities is critical to protecting public health and the environment. Improper handling of medical waste can lead to environmental pollution and pose serious health risks. In Indonesia, Permenkes No. 2 of 2023 provides a regulatory framework for managing medical waste, but its implementation needs to be improved, especially in remote healthcare facilities with limited infrastructure and resources. Technological advances, especially artificial intelligence (AI), offer potential solutions to optimize medical waste management through real-time tracking, sorting, and monitoring.
This study aims to evaluate the role of AI in supporting the implementation of Permenkes No. 2 of 2023 in several health facilities and identify barriers to AI adoption. Using a normative legal approach combined with case studies from health facilities in Indonesia, this study highlights the effectiveness of AI implementation in medical waste management. The results show that AI has the potential to improve compliance with medical waste management standards, optimize waste processing, and strengthen supervision through real-time data collection. However, AI adoption faces high costs, a lack of infrastructure, and limited technical expertise, especially in remote areas.
The implications of this study emphasize the need for investment in technological infrastructure, health workforce training, and supportive policies to address barriers to AI adoption. This would maximize the potential of this technology in more effective medical waste management for public health and a safer environment.
Glass Ceiling in Focus: A Comprehensive Bibliometric Review of Business and Management Studies
Authors: Mahat Dipak
Published: November 2024

The glass ceiling continues to impede women's progression into leadership roles within Business and Management Studies. Despite increased awareness of gender inequality, systemic challenges remain pervasive. This study aims to conduct a bibliometric review to elucidate the trends, key contributors, and geographical landscape related to the glass ceiling from 1999 to 2024. A systematic review methodology was employed, sourcing data from the Scopus database using the keyword "Glass Ceiling." The results indicate a significant uptick in publications post-2017, reflecting increased scholarly attention on gender inequality, influenced by movements such as MeToo. Influential authors, including Senthil Arasu Balasubramanian and Néstor Gandelman, were identified, with the United States leading in geographical contributions, followed by Australia and Spain. New themes such as the "glass cliff" and the unique challenges faced by African women emerged, highlighting the need for a broader focus on intersectionality in future research. The findings reveal an evolving research landscape surrounding the glass ceiling, emphasizing the necessity for interdisciplinary collaboration among scholars. These insights call for targeted initiatives to address barriers to women's leadership advancement. This study offers a comprehensive bibliometric analysis of the glass ceiling phenomenon in Business and Management Studies, charting the evolution of research trends and identifying key authors and geographical disparities. It provides a framework for future investigations into gender inequality in leadership.
Cooperative Competitiveness Index: a tool to assess the competitiveness of agro-industrial cooperatives
Authors: Oliveira Júnior Osmar de Paula , Wander Alcido Elenor
Published: November 2024

Purpose/objective: This paper is a theoretical-methodological effort to propose and describe a new tool for measuring the competitiveness of agro-industrial cooperatives.
Design/methodology/approach: A three-stage procedure was developed: the first step consisted of carrying out a diagnosis of agro-industrial cooperatives; in the second stage, 38 competitiveness sub-factors were identified, and these were grouped, according to common characteristics, under five drivers (cooperative management and governance, production, commercialisation, transaction costs and cooperating farmers); and third, qualitative criteria and tools were presented for the allocation of relative weights and scores, enabling the calculation, on a scale between 0 and 10, of the Cooperative Competitiveness Index (CCI).
Findings: It is possible to mention at least four highlights provided by this study: (1) identification of 38 competitiveness sub-factors for agro-industrial cooperatives; (2) calculation, on a scale between 0 and 10, of the Cooperative Competitiveness Index, using five competitiveness drivers, with their respective relative weights and scores; (3) CCI can be a management tool for agro-industrial cooperatives; and (4) CCI is suitable for the empirical application, with easy adjustments and improvements.
Research limitations/implications: the lack of realisation of the empirical test and calibration of the proposed model and the relative arbitrariness in determining the five drivers of competitiveness.
Originality/value: There is an expectation that the application of the tool presented here can contribute to identifying improvement points, which allow the strategic realignment of the cooperative ventures, improving their efficiency and, consequently, their competitiveness.
Encontrando valor no desperdício: Iniciativas de Economia Circular em ONGs no Brasil e Togo para redução de resíduos alimentares
Authors: Ouro-Salim Omar , Streit Jorge Alfredo Cerqueira , Fanho Ayawovi Djidjogbe
Published: November 2024

Objetivo: Os resíduos de alimentos podem ser reaproveitados por meio de métodos como compostagem, logística reversa e digestão anaeróbica, usando técnicas da Economia Circular (EC). Este estudo visa analisar a aplicação da Economia Circular por ONGs no Brasil (Ecozinha) e Togo (ENPRO) para lidar com o desperdício de alimentos.
Metodologia:  Fazendo uso do framework ReSOLVE analisou-se dados elaborados de duas maneiras: Análise documental e aplicação de questionários. Quatro gestores responderam completamente os questionários (Google Forms), sendo dois de cada país.
Resultados: Ambas as ONGs utilizam abordagens regenerativas, convertendo resíduos em adubos para melhorar o solo e a produção de alimentos. A Ecozinha (Brasil) atua como intermediária na destinação adequada de resíduos, enquanto a ENPRO (Togo) coleta e transforma resíduos orgânicos em produtos agregados. A Ecozinha auxilia estabelecimentos a gerenciar seus resíduos, promovendo a Economia Circular. A ENPRO, por sua vez, valoriza resíduos melhorando o saneamento básico. As duas ONGs analisadas adotam compostagem para fechar o ciclo de materiais, compartilhando compostos com agricultores.
Implicações teóricas: A aplicação de uma estrutura teórica em um caso empírico releva novas formas de análise. Adicionalmente, são sugeridas pesquisas posteriores para a criação de sistemas alimentares mais resilientes, justos e eficazes.
Implicações práticas: O levantamento de oportunidades, barreiras e a elaboração de um framework ilustrando a relação colaborativa contribuem para a tomada de decisão de produtores, empresários e governo.
Originalidade: Até o presente momento, não se encontram estudos que abordem a valorização e a transformação de resíduos alimentares por organizações não governamentais nos países em desenvolvimento.
The state of the art on social interactions in virtual project teams
Authors: Calçada Junior Laurival Siqueira , Vils Leonardo , Chaves Marcírio
Published: November 2024

Purpose: This paper presents a better understanding of the state of the art of social interactions in virtual project teams based on comprehensive literature.
Methodology: This literature review comprises 125 articles from 2017 to October 2023.
Findings: We show that knowledge sharing, social identity, team cognition, psychological safety, and absorptive capacity are adopted to improve understanding of social interactions in virtual project teams.
Practical implications: The conclusions can help managers understand the factors that drive effectiveness in project management and their main barriers. The identified factors represent the focus of the research in the literature.
Originality: This study is original for integrating the themes of social interactions and virtual project teams and for the analysis at three levels: selected articles, most cited articles, and systematic reviews present in the sample. Knowledge sharing is emphasized as the only recurrent theme across all three levels of analysis and research agendas.
Relação entre as práticas da economia circular e a inovação em processos: uma análise nas organizações têxteis de Santa Catarina
Authors: Langa Emanuel Devigili , Tenfen Glaucia Marian , Carvalho Luciano Castro de
Published: November 2024

Objetivo: verificar a relação entre as práticas de economia circular (EC) e a inovação em processos na indústria têxtil.
Metodologia: o estudo utilizou um questionário composto pelas dimensões inovação em processos e EC, aplicado em uma amostra de 135 empresas da indústria têxtil. A análise dos dados foi realizada pela Modelagem de Equações Estruturais (MEE).
Descobertas: evidencia-se uma relação positiva entre as práticas de EC com a inovação em processos, os resultados apontam uma relação positiva. Os resultados mostram que as indústrias têxteis pesquisadas estão em fase inicial de implementação de suas práticas de EC.
Limitação da pesquisa: utilização de uma amostra não probabilística, desse modo, inviabilizando a geração dos resultados obtidos e pela abordagem apenas da inovação em processo.
Implicações teóricas: desenvolvimento e validação psicométrica das questões que norteiam o estudo da aplicação da economia circular, por meio do modelo ReSOLVE, bem como, a integração com o constructo de inovação em processos.
Implicações sociais: ao aplicar os princípios da economia circular por meio do modelo ReSOLVE há otimização da produção e, aliado ao desenvolvimento tecnológico, as indústrias têxteis obtêm melhores resultados de inovação em processos.
Implicações gerenciais: as evidências reais da aplicação do modelo ReSOLVE mostram a relação de causa e efeito entre a economia circular e a inovação em processos.
Originalidade/valor: a relação teórica entre EC e inovação e processo de validação psicométrica das questões que norteiam o estudo da aplicação da EC, por meio do modelo ReSOLVE.
Efeitos do burnout na carreira dos profissionais de controladoria
Authors: Barros Letticia Pinheiro de Oliveira , Trevisan Leonardo Nelmi , Veloso Elza Fátima Rosa , Treff Marcelo Antonio , Barros Neto João Pinheiro de
Published: November 2024

Objetivo - Essa pesquisa se concentrou exclusivamente nos profissionais da área de controladoria, devido à elevada exposição desse grupo a níveis intensos de estresse e pressão e teve como objetivo identificar os efeitos do burnout em suas carreiras. Os objetivos específicos incluem investigar as causas do burnout, analisar os efeitos físicos e mentais na saúde e bem-estar, avaliar seu impacto na produtividade e desempenho profissional, examinar estratégias de prevenção e intervenção e investigar suas consequências na satisfação no trabalho e nas intenções de turnover.
Método - A pesquisa é qualitativa e utilizou entrevistas semiestruturadas na coleta de dados, utilizou-se a análise de conteúdo para analisar os dados e o software NVivo para organizar os dados transcritos.
Resultados - Os resultados enfatizam a importância do autocuidado, do suporte psicológico e de um ambiente de trabalho saudável e equilibrado, onde os profissionais possam se sentir valorizados e motivados.
Contribuições práticas - Espera-se que os resultados desta pesquisa contribuam para o conhecimento sobre o burnout na área de controladoria, fornecendo insights valiosos para a prevenção e intervenção nesse fenômeno. Espera-se que essas descobertas inspirem ações efetivas por parte das organizações, visando promover a saúde mental e o bem-estar dos profissionais, resultando em uma força de trabalho mais saudável, engajada e produtiva.
Originalidade - A originalidade deste estudo reside em abordar o burnout especificamente na área de controladoria, considerando de forma integrada tanto os fatores organizacionais quanto os aspectos individuais.
Peranan Empati Sebagai Mediator dalam Hubungan Antara Burnout dan Self-Efficacy pada Guru Sekolah Dasar di Jakarta
Authors: Margaretha Ineke Putri , Sahrani Riana , Heng Pamela Hendra
Published: November 2024

Guru saat ini tengah menghadapi transisi sistem pembelajaran online ke pembelajaran tatap muka. Hal ini tentunya membuat guru mengalami stres yang menumpuk sehingga berpotensi besar untuk burnout. Teachers’ burnout adalah respon berkepanjangan terhadap stres emosional di tempat kerja. Situasi ini pada akhirnya akan berdampak negatif kepada teachers’ self-efficacy, yaitu menurunnya keyakinan seseorang terhadap kemampuannya sendiri. Sementara teachers’ self-efficacy memiliki hubungan positif terhadap teachers’ empathy, dimana teachers’ empathy adalah kemampuan seseorang untuk merasakan apa yang orang lain rasakan. Hal inilah yang mendasari peneliti memilih teachers’ empathy sebagai mediator terhadap hubungan antara teachers’ burnout dan teachers’ self-efficacy. Penelitian ini menggunakan pendekatan kuantitatif korelasi dan non eksperimen dengan mengumpulkan data melalui kuesioner yang disebarkan kepada 121 guru Sekolah Dasar di Jakarta, berusia 21-55 tahun, dan mengajar kelas 1-6 SD. Self-Efficacy Scale digunakan untuk mengukur tingkat self-efficacy guru, kemudian Manual Burnout Assessment Tool (BAT) untuk mengukur teacher burnout, sementara The Basic Empathy Scale in Adults (BES-A) dipakai untuk mengukur empati guru. Berdasarkan hasil penelitian didapatkan tiga temuan, yaitu terdapat hubungan yang negatif antara burnout kepada self-efficay guru sekolah dasar di Jakarta (β = -0,3216, p = 0,0035), kemudian burnout dapat berpengaruh negatif kepada empathy pada guru sekolah dasar di Jakarta (β = -0,377, p = 0,0032), dan yang terakhir empati berperan sebagai mediator antara burnout dan self-efficacy pada guru sekolah dasar di Jakarta (β = -0,0013, p = 0,9411).
Study of three integrable extensions of Kadomtsev―Petviashvili, Boussinesq, and Kadomtsev―Petviashvili―Boussinesq equations
Authors:   Department of Mathematics, Saint Xavier University, Chicago, IL 60655, USA, ABDUL-MAJID WAZWAZ
Published: November 2024

We study three (2 + 1)-dimensional extensions of Kadomtsev–Petviashvili (eKP) equation, Boussinesq (eBO) equation, and Kadomtsev–PetviashviliBoussinesq (eKP-eBO) equation that appear in many physical settings in dissipative
media. The Painleve test is employed to confirm the integrability of each proposed ´
model. We furnish dispersion relations, phase shifts, and multiple soliton solutions for
each extended model. The bilinear form of each equation will be used to explore a class
of lump solutions for these equations using distinct values of the parameters.
Confinement impacts of magnetic field on ground and low-lying excited doublet states of plasma-embedded lithium atom
Authors:   Department of Mathematics and Computer Science, Faculty of Science, Alexandria University, Egypt, S. DOMA , G. ROSTON ,   Department of Physics, Faculty of Science, Alexandria University, Egypt, M. AHMED ,   Department of Physics, Faculty of Science, Alexandria University, Egypt
Published: November 2024

A first-time study is made for the ground and excited states of plasma-embedded lithium atom in the presence of a homogeneous magnetic field by using the variational Monte Carlo method. The low-lying excited doublet states considered are 1s 2ns, 1s 2np, and 1s 2nd states, whereas the used plasma potentials are the screened Coulomb (SCP) and exponential cosine screened Coulomb (ECSCP) potentials. The energy eigenvalues are assessed by choosing suitable trial wave functions, including the correlated (electron-electron repulsion) and spin parts, in
addition to an effective plasma factor regarding the wave function of the ECSCP model. Using the two plasma models, an interesting relative ordering for the lithium atom reports the results.
Photoluminescence and thermo-stability of polymer composite nanomaterial [Eu(μ2 ̶ OC2H5)(btfa)(NO3)(phen)]2⋅phen/PEPC
Authors:   Institute of Applied Physics, Moldova State University, MD2028 Chişinău, Republic of Moldova, V. VERLAN , I. CULEAC ,   Institute of Applied Physics, Moldova State University, MD2028 Chişinău, Republic of Moldova, V. GHENEA ,   1. Institute of Applied Physics, Moldova State University, MD2028 Chişinău, Republic of Moldova
2. Technical University of Moldova, MD2004 Chişinău, Republic of Moldova, O. BORDIAN ,   Institute of Applied Physics, Moldova State University, MD2028 Chişinău, Republic of Moldova, V. ZUBAREVA ,   Institute of Chemistry, Moldova State University, MD2028 Chişinău, Republic of Moldova, I. BULHAC ,   Institute of Chemistry, Moldova State University, MD2028 Chişinău, Republic of Moldova, I. COJOCARU ,   Institute of Applied Physics, Moldova State University, MD2028 Chişinău, Republic of Moldova, M. ENACHESCU ,   Center for Surface Science and Nanotechnology, National University of Science and Technology Politehnica Bucharest, 060042 Bucharest, Romania
Published: November 2024

Nanocomposite (NC) thin films based on a dinuclear coordination
compound [Eu(μ2 – OC2H5)(btfa)(NO3)(phen)]2·phen and poly-N-epoxypropylcarbazole
(PEPC) have been obtained by chemical methods. Photoluminescence (PL) spectra of
the NC reveal characteristic atomic-like narrow emission bands associated with internal
4f–4f radiative transitions of Eu3+ ion, 5D0,1→7FJ (J = 0–4). The excitation spectrum
of the complex contains a broad band (≈ 300–500 nm) related to the matrix, as well as
a number of narrow excitation bands, determined by the internal transitions within the
Eu(III) ion (463.6, 532.4, 578 nm). Thermogravimetry analysis and differential scanning
calorimetry of the NC show a tendency to higher thermal stability compared to the
original complex, and almost the same PL radiative parameters. PL quenching appears
at concentration of about 10%, as expected based on literature data. The pattern of
excitation and emission spectra of the NC indicate that it can be effectively excited by
a blue-light source 405 nm, which fits well existing cheap blue-light LED sources.
Digital electricity experiments with Raspberry Pi
Authors:   University of Bucharest, Faculty of Physics, Atomistilor Street 405, 077125, Bucharest, Romania, BOGDAN GHERASIM , OVIDIU TOMA ,   University of Bucharest, Faculty of Physics, Atomistilor Street 405, 077125, Bucharest, Romania, CRISTINA MIRON ,   University of Bucharest, Faculty of Physics, Atomistilor Street 405, 077125, Bucharest, Romania, ȘTEFAN ANTOHE ,   1. University of Bucharest, Faculty of Physics, Atomistilor Street 405, 077125, Bucharest, Romania
2. Academy of Romanian Scientists (AOSR), Ilfov Street 3, 050045, Bucharest, Romania
Published: November 2024

In the frame of digitization of didactic experiments, two physics experiments (Ohm’s law and Peltier effect) were performed using Raspberry Pi single-board computer. In both experiments relevant graphs to illustrate the studied phenomena were obtained. Since high school students show more motivation to learn new concepts from the science of physics when these concepts are clearly displayed by the aim of digital techniques, we believe that this kind of didactical approach could be very useful. The benefits of incorporating digital technologies in teaching physics, such as increased student motivation and interest, improving the conceptual understanding and enhancing students problem-solving skills were also highlighted.
Analyze the performance of horns with complex working surfaces used in ultrasonic welding of car turn signals
Authors: Ngo Nhu , Dang Anh , Nguyen Dinh
Published: November 2024

Ultrasonic plastic welding technology has been widely applied in practice. Welding horn design is one of the important tasks. Many studies have presented this problem. However, most of these studies are only interested in face profiles that are flat or have symmetrical profiles. Meanwhile, ultrasonic welding horns with complex working surfaces receive little attention. This research presented the design of an ultrasonic horn with a complex working surface. Moreover, the influence of the slot width in the horn, an important design parameter, on the performance of the designed horn was considered. The finite element method was used for modal and harmonic analysis. The performance of the design was assessed through criteria that are the uniformity of amplitude, the distribution of the greatest stress at points on the working surface, and closed to the target frequency. A new parameter, namely Displacement unevenness (a), was proposed to evaluate the unevenness amplitude in the working surface of the horn. Effects of three alternative slot structures width corresponding values of 12 mm, 17 mm and 20 mm, denoted by B12, B17, and B20 respectively were carried out. The results showed that the B12 and B17 designs have natural frequencies close to the target frequency of the welding machine, while the natural frequency of the B20 design is far from the target one. The B12 and B17 designs also produce an unevenness amplitude smaller than those of the B20 design. The model showing the relationship between design parameters and the required criteria must be further developed. Additionally, this result can be said for the design guidelines not fully available in the literature.
The Diagnostic Value of MicroRNA-499 in Acute Myocardial Infarction: A systematic review and meta-analysis
Authors: Zhang Zhiyuan , Yan Feifei , Dong Zichao , Du Hong
Published: November 2024

Background: The objective of this study was to assess the diagnostic efficacy of MicroRNA-499 in cases of acute myocardial infarction.
Methods: On May 6, 2023, four electronic databases PubMed, Embase, Web of Science, and Cochrane Library were searched with no time restriction. Quality assessment was conducted using QUADAS-2. Random-effects meta-analysis was employed to combine sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). The evaluation of publication bias was conducted through the utilization of Deeks' asymmetry test on the funnel plot.
Results: The studies that were included in the analysis, encompassing sample sizes ranging from 63 to 1155, exhibited a pooled sensitivity of 0.88 and a specificity of 0.97. The pooled positive likelihood ratio (PLR) was determined to be 29.78, while the negative likelihood ratio (NLR) was found to be 0.13. Furthermore, the pooled diagnostic odds ratio (DOR) was calculated to be 236.10. The area under the curve (AUC) was reported as 0.98.
Conclusions: MicroRNA-499 exhibits high sensitivity and specificity for diagnosing Acute Myocardial Infarction, indicating its potential as a valuable diagnostic biomarker.
Confirmation bias in law enforcement and how debiasing interventions and mitigation strategies might help rebuild public trust: A thematic review
Authors: Segovia Richard
Published: November 2024

Purpose. This thematic review examines how confirmation bias impacts decision-making and investigative outcomes in law enforcement, aiming to identify strategies to mitigate these effects. By synthesizing the existing research, this work highlights the challenges of confirmation bias and proposes practical interventions to improve fairness and accuracy in policing. Methods. Text and abstract searches were conducted using Google Scholar, Hein Law Journal Library, and the Ehrhorn Law Library. The focus was on the studies examining decision-making, investigative outcomes, and methods to mitigate biases in law enforcement practices. This review followed the established thematic review methodologies. Results. The literature search produced a variety of qualitative and quantitative studies. The impact of confirmation bias on decision-making, its effects on investigative outcomes, effective mitigation strategies, the role of organizational culture, and its influence on community relations were themes identified after analysis. Conclusions. This review shows the need for thorough research to validate the effectiveness of strategies designed to mitigate confirmation biases in law enforcement. Future studies should include a longitudinal focus on the impact of debiasing techniques, training programs, and organizational changes. Application in Law Enforcement. For law enforcement agencies, implementing targeted training programs, de-biasing techniques, and decision-making models might improve equity and fairness concerning law enforcement practices. Addressing confirmation bias enhances investigative outcomes, builds community trust, and reinforces fairness when applying the law. Law enforcement agencies should consider adopting the strategies discussed in this review to promote more effective and ethical policing practices.
Effect of near-fault vertical seismic excitation on the response of long-span continuous deck truss bridges
Authors: Benmahdi Khaled , Lahbari Noureddine , Rahal Nacer , Demdoum Abdellah , Sadoun Mohamed , Beghdad Houda
Published: November 2024

Introduction/purpose: This study investigates the seismic response of longspan continuous deck truss bridges under the effect of near-fault vertical ground motions. The primary objective is to assess how near-fault vertical seismic excitation affects the structural safety and performance of these bridges. By exploring the nuanced dynamics induced by near-fault vertical motions, the research aims to improve the understanding of the vulnerabilities and challenges faced by long-span continuous deck truss bridges during seismic events. Methods: To achieve this objective, the truss bridge was subjected to a series of ground motions, representing natural seismic events. The seismic response of the bridge was investigated by applying the linear time history method to the 3D finite element model. This analysis focused specifically on the evaluation of base shear and displacement. The analysis was extended to include the seismic performance of truss structures. The comparison between the bridge responses with and without consideration of the vertical component of ground motion was made to clarify the effect of vertical excitation. Results: The results show that there is a significant contribution of vertical excitation, particularly concerning the internal force in the truss elements, where it exceeded 60 % during a severe earthquake, and consequently increased the demand-to-capacity ratio in most elements of the truss bridge structure. Conclusion: For structural engineers and designers, the results of this research suggest that neglecting to include the vertical ground motion component in the analytical assessments of this type of bridges can lead to a greater degree of uncertainty and risk, particularly in near-fault regions.
Mechanical behaviour of austenitic stainless steel loaded in the aqueous solution of H2SO4 during tensile testing
Authors: Abboub Amar , Aboura Ahmed , Benmahdi Khaled , Sadoun Mohamed , Belkacem Mokhtar , Semsoum Djameleddine
Published: November 2024

Introduction/purpose: Stainless steels have excellent corrosion resistance and adequate mechanical properties. However, their use in aggressively hydrogenated environments in the energy industry causes a loss of ductility. This work studied the effect of hydrogen on the mechanical behavior of the DINX15CrNiSi25.21/AISI310 austenitic stainless steel loaded in an aqueous solution of purely sulfuric acid H2SO4 at 1N at room temperature during tensile testing. Methods: Experimental characterization techniques are applied to standardised machining-manufactured tensile specimens which underwent a series of heat treatments ranging from quenching at 1050°C for 35 minutes to tempering at 680°C for 30 minutes. This is accompanied by a succession of immersions of these samples by cryogenic quenching cycles at -196°C for a duration of 1 hour. The hydrogen was electrolytically loaded in a Pyrex glass cell for various loading times, ranging from 1h00 to 15h00, with a step of 2h00. Results: The results showed a reduction in mechanical properties and plasticity. The electrochemical method confirmed the material's sensitivity to hydrogen embrittlement, calculating the embrittlement criterion EI (%). This method indicates a rapid increase in values depending on hydrogen loading times, with a maximum value of 41.60%. Conclusion: The study highlights the negative impact of hydrogen on the mechanical properties of AISI310 stainless steel, emphasising the need for reduced hydrogen exposure in steel applications.
Determination of a model of preventive maintenance of special purpose vehicles
Authors: Biočanin Stojko , Timotijević Milica , Bulatović Željko , Mišić Milan
Published: November 2024

Introduction/purpose: The aim of this paper is to obtain quantitative and qualitative indicators of vehicle condition and reliability based on operational data which can be used to determine the optimal periodicity of preventive maintenance for special purpose vehicles, and to more accurately manage the maintenance process and the operational readiness of these vehicles. Methods: Based on operational failure data and statistical methods, a mathematical model of the reliability of special purpose vehicles was determined. Using this model and operational data, the periodicity of preventive maintenance for the vehicles was determined through multicriteria optimization, considering both readiness and minimum maintenance costs. The same methodology was applied to determine the optimal preventive maintenance periodicity for 15 components of the mechanical system of special purpose vehicles. A group analysis was conducted using Minitab 15 statistical software, based on the theory of similarity in preventive maintenance periodicity for the 15 components, and a statistical analysis of the conducted research was performed using Minitab 16 statistical software. Results: Models for preventive maintenance of special purpose vehicles were developed based on the recorded vehicle failures and the failures of fifteen vital components. A group analysis grouped the fifteen components into optimal maintenance groups, similar in terms of working time between failures. The statistical analysis of the research determined a functional relationship for the optimal periodicity of preventive maintenance for special purpose vehicles. Conclusion: The maintenance periodicity obtained through multi-criteria analysis is optimal, as it achieves satisfactory vehicle readiness with optimal maintenance costs. The statistical analysis of the research concluded that the maintenance periodicities of the vehicle components are different. In both fleets, the engine and the transmission block have the longest maintenance intervals. The research results can be used to rationalize the existing preventive maintenance concept.
A computer vision approach with OpenCV and deep learning for determining inductance in planar coils
Authors: Benazzouz Younes , Guendouz Djilalia
Published: November 2024

Introduction/purpose: In the realm of development and use of computer vision and AI methodologies, this research introduces a combination and advanced method using YOLOv9, a deep learning concept of whole image processing in one pass through a convolutional neural network (CNN) and the OpenCV Python image processing library to determine the geometry of planar coils. These geometric parameters are the main parameters used to calculate the inductance value using Mohan's formula, which exclusively utilizes only geometric data to estimate inductance values. This method significantly speeds up the verification and calculation processes, while also playing a role in improving quality control after manufacturing. Methods: The methodology is divided into two main phases. Initially, a YOLOv9 model was trained for object recognition using a generated synthetic dataset of coil shapes created with Python's Turtle graphics library. Then, after the detection phase, OpenCV was used to identify the geometric parameters of the images. The pixels were converted into millimeters using a ratio method to calculate the inductance value accurately. Results: The YOLOv9 model successfully identified various planar coil shapes, and the geometric parameters were identified through OpenCV. Subsequently, the inductance was successfully calculated. Conclusion: The results show that the proposed method is a novel and effective way of calculating inductance.
Modification of synthetic polyisoprene by combination with high-density polyethylene
Authors: Chernyshov Sergey , Lyusova Lyudmila , Zharylganova Manizha , Nebratenko Dmitry
Published: November 2024

Introduction/purpose: The development of elastomeric materials based on synthetic polyisoprene (IR) with high green strength is a rather urgent task, because it allows to replace, completely or partially, the main ingredient - natural rubber in responsible rubber products. The aim of the work was an additional increase in the green strength values of IR and rubber mixtures based on it by its modification with high-density polyethylene of PND 277-73. Methods: The main methods of the research of the technological, physicalmechanical and operational properties were used. All tests conformed to ASTM or ISO standards. Rubber compounds were made in the Haake PolyLab rubber mixer. In parallel with the effects of modification, the influence of the mixing temperature on the main properties of IR and NR based elastomeric materials was investigated. Results: It is shown that the increase in the mixing temperature of NR and IR for 20ºC leads to significant changes in the technological properties of rubber compounds (primarily green strength), as well as the physicalmechanical and operational properties of cured rubber. It has been established that a significant increase in the green strength of the rubber compound is achieved by combining IR with 7 mass. % HDPE. Conclusion: The developed polymer composition based on IR and HDPE has a level of green strength of the rubber compound 2 times higher than that of natural rubber, while maintaining the physical-mechanical and operational characteristics of cured rubbers at the level of natural rubber. The polymer composition IR/HDPE 93/7 can be recommended for use in the manufacture of products whose manufacturing technology requires increased green strength of rubber compounds, including largesized and all-metal tires.
Effect of some parameters on the separation process of a saboted bullet
Authors: Bui Xuan , Nguyen Quang , Nguyen Hai
Published: November 2024

Introduction/purpose: In this paper, the influence of muzzle velocity and the initial friction between the sabot and the penetrator of a sub-caliber bullet on the separation process was investigated. A special armor-piercing bullet was chosen as a research object. Methods: A hybrid approach was applied in the study to solve the set tasks. In the first place, the equation system describing the motion of the sabot and the penetrator was established analytically. The aerodynamic drags acting on the sabot and the penetrator were then obtained numerically using CFD methods. Eventually, the equations of motion of the sabot and the penetrator were solved using the Runge-Kutta method to analyze the effect of the bullet muzzle velocity and the initial friction of the sabot and the penetrator on the separation process. Results: The research results have shown the significant influence of the bullet muzzle velocity and the initial friction on the parameters of the sabot and the penetrator at the very moment they completely separate from each other. Based on the obtained data, weapon designers can appropriately select the ballistic and structural parameters for the bullet. Conclusion: The hybrid approach presented in this paper is effective in studying the separation process of armor-piercing saboted bullets. The research results are useful contributions to the field of sub-caliber ammunition. The presented method can be applied in the design process of armor-piercing saboted projectiles of different calibers.
Models of microeconomic dynamics: Bifurcations and complex system behavior algorithms
Authors: Malyarets Lyudmyla , Dorokhov Oleksandr , Voronin Anatoly , Lebedeva Irina , Lebedev Stepan
Published: November 2024

Introduction/purpose: Studying the dynamics of the mutual influence of supply and demand is relevant in connection with the financial losses that arise due to uncertainty in demand and forecast errors. The work aims to build a mathematical model of the dynamics of this interaction for the market of one product. Methods: The paper proposes a mathematical model of the states of the supply-demand system, within the framework of which the processes occurring in this system are considered from the perspective of the methodology of economic synergetics. The mathematical model of dynamics has the form of a system of two differential equations with quadratic nonlinearity. Results: The use of the proposed model to reproduce various dynamic states of market self-regulation processes made it possible to identify the hierarchy of transition from stable dynamic regimes to unstable ones with the appearance of corresponding bifurcations. The main attention was paid to studying the behavior of the system at the boundaries of the stability region. Conclusion: The existence of a saddle-node bifurcation of limit cycles has been revealed, which suggests the appearance of stable self-oscillations in the case of a "soft" cycle and unstable ones in the case of a "hard" cycle. When studying a bifurcation of codimension two - "double zero" - special dynamic structures were discovered, determined by the properties of global bifurcations. This type of behavior is characterized by self-oscillations with a low frequency, which gives rise to the so-called "ultra-long waves" of the economic state.
Design and performance of a manual extruder for recycled plastic-brick composite pavers
Authors: Daikh Abdelkader , Moulai Arbi , Bentahar Mohammed , Mahmoudi Noureddine
Published: November 2024

Introduction/purpose: This study aimed to develop a cost-effective manual plastic brick extruder for manufacturing composite bricks from recycled polypropylene and brick powder. The goal was to address housing challenges in developing countries while promoting sustainable waste management. Methods: A single screw extruder with a 60 mm die was fabricated, featuring a manual crank, a heating system, and a hopper. Composite specimens with varying polypropylene (30-80 weight percentages) and brick powder (20-70 weight percentages) ratios were produced. Mechanical testing was conducted, including compressive strength, flexural strength, impact resistance, and density measurements. Results: The 40:60 polypropylene:brick powder mixture exhibited optimal compressive strength, ranging from 23.76-24.90 MPa. Flexural strength peaked at the 50:50 ratio (11.86-12.5 MPa). Impact resistance decreased with increasing brick powder content. Density increased linearly with brick powder content, ranging from 1.48-1.77 g/cm³. The extruder successfully produced uniform composite specimens across all mixtures. Conclusions: The study demonstrated the feasibility of producing composite bricks using a low-cost, manually operated extruder. Two optimal mixture compositions were identified: 40:60 polypropylene:brick powder for maximum compressive strength and 50:50 for optimal flexural strength. This approach offers a promising solution for affordable housing construction while addressing plastic waste management in developing regions. Future research should focus on optimizing the extrusion process, exploring additional waste materials, and conducting long-term durability studies of composite bricks.
A model for evaluating menu performance in collective nutrition organizations based on the DEA method
Authors: Arsić Slaviša , Pamučar Dragan , Milenkov Marjan , Sokolović Vlada , Janošević Miljojko
Published: November 2024

Introduction/purpose: In the paper, a model for evaluating menu performance in collective nutrition organizations is presented, enabling quantification of the efficiency of each individual dish. Methods: The Data Envelopment Analysis (DEA) method has been applied to evaluate the efficiency of dishes. Results: The model has been successfully tested on the menu of the collective nutrition restaurant for cadets at the Military Academy in Belgrade (MAB). The evaluation included 20 existing dishes and 11 substitute dishes formed using the Food Replacement Table (FRT), allowing insight into the efficiency of each individual dish. In line with the specified criteria, 10 out of a total of 31 dishes have been evaluated as efficient (7 existing and 3 replacement dishes). By replacing inefficient existing dishes with new efficient dishes, the overall efficiency of the menu will increase, implying greater satisfaction of food users and reduction of the waste of prepared and uneaten meals. Conclusion: A proposed model can be applied in practice because it provides objective and measurable values for assessing the performance of dishes, aiming to optimize the menu assortment in collective nutrition organizations and reduce the shortcomings of subjective decision making in selecting substitute meals. This model can be further improved by the use of other different methods for determining the weights of the criteria and ranking.
Efficiency assessment of different highspeed tracked vehicle hybrid powertrain conceptions
Authors: Ponorac Luka , Blagojević Ivan
Published: November 2024

Introduction/purpose: Increased development of hybrid powertrains during the last decade brought high-speed tracked vehicles into the same spotlight as commercial and passenger hybrid vehicles. There are several hybrid powertrain conceptions for high-speed tracked vehicles that are mainly researched, but there is still no clear conclusion which conception is the most efficient. The main obstacle for more intense research is the increased difficulty to produce a battery storage system which provides both high power density and protection and shock resistance. However, there is a certain number of research studies and prototypes developed from simulation models that show satisfactory performance for both asymmetric and symmetric hybrid powertrain conceptions. Methods: The developed and verified hybrid simulation model is improved in terms of command signal unit, so that the powertrain and electric motors in the auxiliary drive can easily be operated in the asymmetric hybrid working regime and the symmetric hybrid working regime. The main goal is to simulate specific working regimes where the asymmetric and symmetric hybrid powertrain performance and energy efficiency can be assessed in order to find the most efficient powertrain conception. Results: The results indicate that the asymmetric hybrid powertrain will have less overall power consumption and a more simple control algorithm, because of controlling just one electric motor. For the same overall power, the asymmetric hybrid powertrain has a smaller turning radius, which is satisfactory. When driven in full power, the symmetric hybrid powertrain will have lower turning radius and better manoeuvrability, but serious increase of power consumption. Conclusion: The asymmetric drive has clearly better power efficiency, but the symmetric drive has an advantage of maximum performance. Performing a pivot turn (around the vertical axis), and making a turn without reducing the vehicle velocity is of great importance, especially considering the most common special purpose of this vehicle and manoeuvring in challenging terrain conditions.
Corrosion of Zn-Ni coated reinforcing steel in simulated concrete pore solutions
Authors: Bučko Mihael , Radović Ljubica , Dimitrijević Marko , Karkalić Radovan , Bajat Jelena
Published: November 2024

Introduction/purpose: The anticorrosion protection of steel reinforcement bars in concrete is a critical concern in civil engineering, particularly for the construction of concrete structures intended for military applications. Currently, the most important methods for achieving this protection include the application of coatings on steel rebar (such as epoxy or hot-dip galvanized zinc), the use of stainless-steel rebar, composite rebars, or high performance concrete that incorporates corrosion inhibitors, surface sealers, silica fume, or fly ash admixtures. Methods: This study aims to determine whether an electroplated Zn-Ni coating of sufficient thickness can offer better long-term corrosion resistance to reinforcing steel in concrete compared to the traditional pure Zn coating typically used for this purpose. The Zn-Ni coatings produced were 40 µm thick and contained approximately 13 mass.% Ni. Scanning electron microscopy revealed a smooth and homogeneous surface morphology, although microcracks extending through the entire coating depth were observed. The protective effectiveness of the coatings was evaluated using electrochemical impedance spectroscopy, with samples immersed in various electrolytes that simulate the chemical environments present in different types of concrete. Results: The measurements indicated a significantly slower dissolution rate of the corrosion product formed on the Zn-Ni coating in chloride-rich environments, compared to pure Zn. Conclusion: It can be concluded that Zn-Ni alloy presents a viable alternative to pure Zn for protecting steel in concrete structures where high chloride penetration is anticipated.