Scientific Bulletin Series C, Volume XXXVIII (2024)
Analysis of Shoch Damping in the Lubricant Film in a Hydrodynamic Radial Bearing
Ioan Marius Alexandrescu, Adina Sorina Alexandrescu
Abstract: In the present study, we investigate the shock behavior of a hydrodynamic radial bearing with L/D ratio 0.5 comparing the effect of spindle speed on the shock absorption in the lubricant film. We performed tests for different static loads, we kept the supply pressure constant, and the results presented refer to the maximum dynamic load F3.
Keywords: lubricant film, radial HD bearing, shock absorption, spindle speed.
Reverse Engineering between Technological Innovation and the Risk of Counterfeiting and Piracy: Conceptual Delimitations and Legal Implication
Bianca Cristina (Pop) Borgyos, Miorița Ungureanu, Raul Florentin Drența
Abstract: Reverse engineering occupies a dual position in the contemporary technological landscape. On one hand, it acts as a catalyst for innovation, facilitating interoperability, performance analysis, and the development of alternative solutions; on the other hand, it can be misused when applied for illicit purposes, such as counterfeiting and piracy. This article aims to clarify the conceptual boundaries between legitimate and illegal practices of reverse engineering through an analysis of the relevant literature and the applicable regulatory framework. The section on legal implications examines the tension between intellectual property rights and the need for technological progress, highlighting the challenges arising from the absence of uniform regulatory standards. The conclusions seek to formulate a balanced perspective that integrates both legal and ethical dimensions, providing guidelines for establishing a coherent framework in which reverse engineering can remain a driver of innovation without undermining intellectual property protection or market fairness.
Keywords: Counterfeiting, Intellectual property, Legal implications, Piracy, Reverse engineering, Technological innovation.
E-Commerce Adoption in Industrial Manufacturing: Evidence from Romanian Firms in the Context of Digital Transformation
Raul Florentin Drența, Andrei Raul Osan, Raluca Georgiana Robu
Abstract: The integration of e-commerce technologies in industrial companies represents both an opportunity and a necessity in the context of digital transformation. This paper investigates the impact of e-commerce adoption in Romanian manufacturing firms, focusing on their attitudes, infrastructural readiness, perceived barriers, and expected benefits. Based on a quantitative study conducted among 58 companies in the North-West region of Romania, the research highlights a growing openness toward digitalization, despite notable challenges related to workforce skills and regulatory gaps. The findings reveal that e-commerce can improve operational efficiency, customer interaction, and global competitiveness. The study proposes actionable insights to support industrial firms in leveraging ecommerce as a strategic development tool.
Keywords: Digital transformation; E-commerce adoption; Industrial competitiveness; Manufacturing sector; SME digitalization.
Technologies for the Treatment of Mine Water
Andrei Enache, Valeria Mirela Brezoczki, Miorița Ungureanu
Abstract: This paper presents an integrated analysis of both conventional and emerging technologies used in the treatment of contaminated waters resulting from mining operations, with a focus on chemical, biological, and advanced solutions such as nanomaterials and the ASEC system. The main purification mechanisms—such as neutralization, metal precipitation, phytoremediation, and the use of passive wetland systems—are highlighted, emphasizing the need to integrate them into a coherent management strategy. Case studies from China, Romania, and Western Europe validate the real-world applicability of these technologies. The results demonstrate that combining chemical and biological treatments within a circular economy model enhances efficiency, reduces environmental impact, and enables the recovery of valuable resources.
Keywords: acid mine drainage, ASEC technology, chemical neutralization, circular economy, nanomaterials, phytoremediation.
Methodological Investigation of Wiper Geometry Inserts’ Influence on Surface Quality and Integrity of Al 7136 Aluminum Alloy in Milling
Cornel Cristian Florian, Alina Bianca Pop and Vasile Năsui
Abstract: This paper addresses the optimization of the milling process for the high-performance aluminum alloy Al 7136 using Wiper geometry cutting tools (inserts). Although milling Al 7136 is a productive method, a constant tradeoff exists between productivity and achieving superior surface quality. The work’s aim is to investigate the detailed influence of Wiper inserts and cutting parameters on a wide range of surface quality indicators. The research questions focus on how the Wiper geometry affects roughness and subsurface integrity (microstructure, defects, residual stresses, hardness), and on identifying the optimal correlations between cutting parameters and these indicators. The proposed experimental research design involves varying the cutting speed, feed per tooth, and depth of cut as independent variables, with measurements of roughness, surface morphology, and microhardness profile as dependent variables. The paper presents the context of the Al 7136 material and the milling operation, defining surface quality beyond roughness to include subsurface integrity. Wiper inserts are introduced as a solution to increase productivity without compromising the surface finish or even improving the finish at standard feeds. The research is motivated by a lack of systematic studies regarding the Wiper effect on the surface integrity of Al 7136. Expected results include identifying optimal milling conditions and understanding the physical mechanisms governing surface formation, contributing to more precise machining guidelines.
Keywords: Al 7136, Milling, Productivity, Roughness, Surface Quality, Wiper Inserts.
Navigating Geopolitical Turbulence: Essential Competence of the Defense Industry Manager
Mihai Georgian, Tudora Alexandru, Miorița Ungureanu
Abstract: This study explores the essential change management competencies required of defence industry leaders and managers in the context of the amplification and complexity of today’s geopolitical turmoil. Examining the direct and indirect impact of major crises, such as the war in Ukraine, the Hamas-Israel conflict, the US administration’s tariff policies, and China’s technological and military rise, the article emphasizes the need for personnel in this strategic sector to develop superior capabilities in anticipation, strategic adaptation, risk management, and international collaboration. By integrating recent literature from the fields of strategic management, geopolitics, security studies, and defence economics, the paper argues that mastering change is no longer an optional skill, but a fundamental competency for maintaining operational superiority, ensuring national security, and navigating effectively in an era of global uncertainty.
Keywords: change management, defence industry, international defence cooperation, operational resilience, strategic leadership.
Design of Experimental Studies by the Taguchi Method
Andrei Raul Osan, Raul Florentin Drenta
Abstract: The research aims to analyze in depth the process of designing experiments by applying the Taguchi method, an approach recognized for its efficiency in optimizing experimental studies. Within this approach, the fundamental steps have been identified and detailed, as well as the specific steps to be followed according to the principles of this method. Thus, a detailed plan for the organization of the experiments was developed, which included the validation of the factors with significant influence on the results, the precise definition of the study parameters essential for the research objectives and the determination of the orthogonal matrix of the experiments, a key tool in ensuring a systematic and efficient approach. Based on these elements, the optimal number of experiments needed to conduct experimental research was determined.
Keywords: Taguchi method, design of experiments, orthogonal matrix, factor validation.
Using the Taguchi Method to Study the Machining of Aluminum-Lithium Alloys Used in the Construction of Airbus A350 Aircraft Structural Components
Nicolae Ioan Pasca
Abstract: The paper presents an experimental and statistical analysis of the machining process of aluminum-lithium alloys used in the aeronautical industry, with the aim of modeling the influence of technological parameters on the durability of the cutting tools. The experiments were planned according to the Taguchi method, using an L36 matrix and five main factors: alloy type, experimental phase (setup), tool type, feed per rotation and cutting tool`s face. Analysis of variance (ANOVA) revealed that the tool type has a dominant contribution (≈85–90%) on the response, followed by feed per rotation (≈10–13%), the other factors having minor influences. The results are confirmed by the analysis of the signalto-noise ratio (S/N) for the “Smaller-the-Better” criterion, indicating a high stability of the process under optimal conditions. The paper also proposes directions for process optimization and a subsequent stage of predictive modeling using artificial neural networks of the multi-layer perceptron (MLP) type. The conclusions obtained contribute to the development of efficient machining strategies for advanced aluminum alloys intended for aeronautical applications.
Keywords: aluminum, analysis, durability, machining, neural, tool.
Experimental research methodology for testing DLC-coated milling tools used in machining parts in the aeronautical industry
Nicolae Ioan Pasca, Mihai Banica, Marius Cosma, Nicolae Ungureanu, Vasile Nasui
Abstract: This paper presents the experimental research methodology used to test milling tools coated with amorphous diamond-like layers (DLC – Diamond-Like Carbon), in order to evaluate their performance in machining processes. The study aims to determine the influence of DLC coating on wear behavior, machining efficiency and surface quality obtained, compared to milling tools. The proposed methodology includes the selection and characterization of milling tools, the definition of machining parameters, the establishment of test conditions and the measurement of output parameters such as surface roughness, durability and tool wear evolution. The experimental results are statistically analyzed to highlight the technological and economic advantages of using DLC coatings in the machining of aluminum alloys. The study contributes to the optimization of milling processes and the extension of tool life.
Keywords: coating, diamond, experiment, research, tool.
Process optimization through advanced technologies
Anamaria Manuela Savu, Nicolae Stelian Ungureanu
Abstract: Optimizing processes through advanced technologies is a strategic imperative for organizations in various economic sectors, aiming at operational efficiency, cost reduction and performance increase. The use of Artificial Intelligence (AI), Internet of Things (IoT), Big Data and industrial automation fundamentally transform processes by analyzing and optimizing data in real time. In the energy sector, IoT facilitates monitoring of consumption and equipment, minimizing losses and increasing efficiency. Early detection of failures and preventive maintenance, based on IoT, contribute to reducing costs and extending the life of infrastructures. The integration of these technologies into energy systems accelerates the digitalization and sustainability of the sector. By optimizing resources and reducing operational risks, emerging technologies support the transition to a more efficient and resilient economic model. The digitalization of industrial processes redefines traditional paradigms, enabling data-driven decisions and increased adaptability. Thus, technological innovations not only improve operational efficiency, but also facilitate the development of a sustainable and competitive ecosystem. Adopting advanced technologies not only optimizes operational flows, but also improves the ability of organizations to respond dynamically to market challenges. The implementation of solutions based on AI and Big Data enables predictive analysis and informed decision-making, reducing uncertainty and increasing competitiveness. Industrial automation contributes to increasing productivity by eliminating human errors and streamlining repetitive processes. In addition, the integration of IoT into critical infrastructures ensures constant monitoring and rapid intervention, preventing major failures and optimizing resource consumption. These technological advances represent the fundamental pillars of digital transformation, facilitating the transition to a sustainable, intelligent and future-oriented operating model.
Keywords: Advanced technologies, Digital transformation, Internet of Things (IoT), Operational efficiency, Optimization, Preventive maintenance, Sustainability.