JOURNAL OF ENGINEERING SCIENCE

ROUNDABOUT – ELEMENT OF SAFETY, ECOLOGY AND ECONOMY

2025-08-06T09:47:17+00:00

Statistical analysis reinforces the conclusion that road accidents are not random and even more unpredictable or unavoidable, although their occurrence is random. The concentration of road accidents at intersections is high, around 25-30% of the total number of road accidents. The intersection itself is an area of concentration of conflict points, where the occurrence of road accidents is both theoretically and practically possible due to the contact of vehicle flows from three different directions: intersecting, separating and merging. Increasing the safety of intersections therefore boils down to taking measures to reduce the number of conflict points and the degree of their potential danger. The article describes the purpose, advantages and disadvantages, conflict points, classification and types of roundabouts. The benefits of roundabout organization in terms of road traffic safety, environmental safety and increasing the road's passing capacity, thus reducing waiting time at intersections, are also analyzed.

THE LIKELIHOOD FUNCTION BASED ON UNCENSORED/ CENSORED STATISTICAL DATA FOR MIN-PSD(MAX-PSD) AND MAX-PSD(MIN-PSD) AS LIFETIME DISTRIBUTIONS IN NETWORK RELIABILITY

2025-08-06T09:52:21+00:00

In this paper general formulas for the likelihood function have been derived in the case when uncensored/censored statistical data refer to the lifetime of serial-parallel and parallel-serial type networks when the lifetimes of the system units are independent, identically distributed random variables, the number of subsystems and the number of units in each subsystem are random variables with power series type distribution. The formulas can be applied to obtain maximum likelihood estimators for the parameters of the lifetime distribution of the mentioned networks. The results are illustrated by examples of concrete probabilistic models.

IN-DEPTH PROPERTIES ANALYSIS OF ZnAl2O4/ZnO MICRO-NANOSTRUCTURES

2025-08-06T09:55:34+00:00

This manuscript presents characterization of ZnAl2O4/ZnO micro-nanostructures of their morphological, chemical, structural and sensing properties. The ZnO micronanostructures obtained using flame transport synthesis were covered with ZnAl2O4 nanodots by chemical approach. Morphological, chemical and structural properties have been investigated using SEM, EDX and XRD, respectively. Scanning electron microscopy investigation shows the formation of micro-nanostructures of different morphologies, namely tetrapods and nanowires, covered with nanodots. The EDX study revealed the chemical composition of the micro-nanostructures, confirming the presence of Al on the micronanostructures’ surfaces too. The XRD pattern of the studied micro-nanostructures shows the presence of ZnO and ZnAl2O4 crystalline phases in the grown material. A single ZnAl2O4/ZnO nanostructure was integrated into a device by FIB/SEM and tested to a series of gases at different operating temperatures, demonstrating selectivity to 100 ppm hydrogen gas and response value of ~1.2 up to ~3.65 at 20 °C and 150 °C, respectively. A sensing mechanism to hydrogen gas was proposed, involving free electrical charge transfer between ZnO wire and ZnAl2O4 nanodots. Based on the knowledge gained, optimization of hydrogen gas sensors using the methods and nanomaterials presented herein is envisioned.

INTERFACE ADAPTATION DESIGN FOR EXTRACELLULAR RECORDINGS FROM EXCITABLE TISSUE

2025-08-06T10:05:10+00:00

For a clear and almost exhaustive perspective on the physiology of living organisms, it is important to use the best method to sample the signal and to process it correctly, without affecting the content of information. Therefore, the method must ensure the best possible sensitivity and selectivity. In this work, a device for processing physiological signals is designed. The main component will be an instrumentation amplifier, whose characteristics meet specific requirements. This is an amplifier suitable for high-quality recording of extracellular signals from muscle and nervous tissue. Its characteristics are related to the fact that it has a gain and bandwidth for the signals of interest, a common mode rejection rate, filtering and low internal noise. The input impedance is high, and the consumption is low are other key features of this device. In addition, the component costs are very low, and the design is very compact. Due to the high input impedance of the amplifier, it adapts very easily to different signals. The final experimental results show the viability of the solution chosen by design.

ENSURING EFFECTIVE MANAGEMENT OF MEDICAL DEVICES THROUGH SAFE USE OF MEDICAL DEVICES AND EVIDENCE-BASED MANAGEMENT

2025-08-06T10:08:25+00:00

To ensure effective management of medical devices, it is imperative that medical devices must be safe and inoffensive, and their management must be based on evidence. Thus, to help enhance the safety of medical devices, a new mechanism for the periodic compliance assessment of medical devices has been developed. The mechanism involves the assessment of general safety, electrical safety and performance parameters in line with international best practice. At the same time, the effective management of medical devices requires data and information related to medical devices and their lifecycle events, which can be obtained through the medical device management information system. The establishment and implementation of efficient management of medical devices, involves strengthening the capacities of medical devices’ management, in order to be able to respond to the current requirements of the health system, in such a way as to ensure the functionality of medical devices and the safe and efficient use of medical devices. Accordingly, the implementation of efficient management of medical devices is fundamental for providing qualitative, safe and efficient medical devices, which contributes to increasing the quality of medical services.

QUANTUM COMPUTING FOR MULTI-QUBIT SYSTEMS USING SCHWINGER REPRESENTATION OF ANGULAR MOMENTUM

2025-08-06T10:11:16+00:00

This paper deals with the features of quantum computing for a system containing a relatively large number of qubits n, which is characterized by a half-integer effective spin S in the Schwinger representation of paired bosons. It was shown that for n = 70, the number of boson states corresponding to lowest 2S + 1 excited energy levels of each of the two harmonic oscillators implementing the two-boson representation of the effective spin S is N = 1070 = 1.18 x 1021. Under such conditions, it can be assumed with great precision that for n ≥ 70 all boson states of both harmonic oscillators participate in the implementation of the two-boson representation of the effective spin S. This allows one to apply the quantum field theory methods when performing quantum computations for multi-qubit systems. Another advantage of the Schwinger representation of paired bosons compared to the spinor representation when performing quantum computations for multi-qubit systems is that in the first case the form of the spin projection operators of the effective spin S does not depend on the number of qubits n.

SECURING MOLDOVAN SMALL AND MEDIUM-SIZED BUSINESSES: STRATEGIES BASED ON IT INFRASTRUCTURE DOMAINS

2025-08-06T10:14:53+00:00

The digitization of small and medium-sized enterprises (SMEs) has accelerated in recent years, increasing their reliance on information systems to support core business operations. ENISA’s 2021 report showed an important growth in SME dependence on IT, while the World Economic Forum ranked cybersecurity failure among the top five global risks. Although digital transformation brings competitive advantages, it also exposes SMEs to cyber threats. A comparative analysis of scientific studies from the UK, Australia, the EU, Malaysia, and the USA identified social engineering, Denial of Service (DoS) / Distributed Denial of Service (DDoS), and Man-in-the-Middle (MitM) attacks as the most frequent threats. This article analyzes the main barriers preventing SMEs from implementing information security frameworks and identifies the lack of national-level regulations in the Republic of Moldova. Based on a structured model developed by the authors, the paper proposes tailored recommendations for improving information system security in Moldovan micro-enterprises. The findings emphasize the need for contextualized, cybersecurity solutions and public policy support targeting risk management and awareness.

CYBER SECURITY PROFESSIONAL DEVELOPMENT WITHIN CYBERCOR

2025-08-06T10:19:43+00:00

One of the main development challenges facing the Republic of Moldova is its vulnerability to state security threats and risks. In the context of the objectives for developing the digital economy and digitalizing public services, measures to counter cyber threats and risks become imperative. Law No. 48/2023 on cyber security stipulates the implementation of requirements, measures, and mechanisms to ensure a sufficiently high level of security for networks and information systems in the Republic of Moldova, capable of guaranteeing the protection of the vital interests of individuals and legal entities, society, and the state, as well as the national interests of the Republic of Moldova. In this regard, the human resources' preparation level plays a primary role and is a priority. Developing cybersecurity skills among staff is an indispensable part of the process of ensuring the cybersecurity of systems and information resources. The creation of the National Institute for Cybersecurity Innovation CYBERCOR aims ultimately to ensure the necessary level of cybersecurity competencies among personnel, strengthening the security of networks and information systems. The appropriate professional development of public authority staff at any level and employees of other legal entities, public or private, will enable the prevention and counteraction of cyber threats and risks.

THE EFFECT OF TORREFACTION ON PELLETS MADE FROM VEGETAL BIOMASS GENERATED BY FRUIT SHRUBS

2025-08-06T10:24:31+00:00

This study investigates the effects of torrefaction on the properties of pellets produced from vegetable biomass residues of fruit shrubs. The research focuses on two pellet formulations: (1) a blend of sea buckthorn (Hippophae rhamnoides L.) and blackberry (Rubus fruticosus) residues and (2) a mixture of sea buckthorn residues with wheat straw. The torrefaction process was conducted in an inert argon atmosphere at temperatures between 200 °C and 300 °C for durations ranging from 10 to 30 min. The study assessed the impact of these parameters on the net calorific value and ash content of the pellets. Results indicate that torrefaction significantly enhances the calorific value of the biomass, with optimal conditions identified at 250-280 °C and exposure times of 15-25 min. However, excessive temperature and duration lead to mass losses and increased ash content. These findings provide insights into optimizing torrefaction parameters for improving the quality of densified solid biofuels derived from agricultural residues.

ADVANCED DRONE-BASED MONITORING OF AGRICULTURAL, FORESTRY, AND AQUATIC ECOSYSTEMS: TECHNICAL FRAMEWORK

2025-08-06T10:29:19+00:00

The rapid advancement of drone technology has significantly transformed environmental monitoring, enhancing capabilities for observing and managing agricultural, forestry, and aquatic ecosystems. This paper presents a comprehensive technical framework for implementing advanced drone-based systems into ecosystem monitoring, focusing on integrating high-resolution sensors, data processing, and artificial intelligence-based analytics. The framework incorporates modern technologies, including drones from Da-Jiang Innovations or First-Person View drones equipped with metric cameras for aerial photogrammetry. These can be further enhanced with multispectral and Light Detection and Ranging sensors to acquire real-time data, enabling more effective analysis. Furthermore, the Proxmox Virtual Environment is the core of the system’s architecture, increasing effective virtualisation and deployment. Core data processing technologies include Python scripts, Quantum Geographic Information System, and Pix4D software for photogrammetric reconstruction, as well as Elasticsearch for database management, acquisition, and storage. The Kibana platform ensures interactive data visualisation and supports evidence-based decision-making. The service-oriented structure and system modularity enable the rapid integration of new analytical tools that are adaptable to diverse ecological contexts. Validation in operational environments confirms the framework’s ability to address challenges in ecosystem management, particularly in remote areas. This integrated approach contributes to more sustainable and adaptive ecosystem monitoring and management practices.

MOLECULAR DIAGNOSTICS OF SOIL-BORNE PATHOGENIC FUNGI IN SEVERAL AGRICULTURAL CROPS

2025-08-06T10:32:07+00:00

Modern requirements for product quality provide for expanding the competence in sectors of producing and managing agricultural products by investigating the cause-effect relationships in the transmission of diseases between species through host-pathogen interactions. Monitoring and accurate identification of pathogens in agriculture products are essential for successful implementation of an integrated pest management program. Among the pathogens that have a serious impact on agricultural production, micromycetes outnumber all other species. Diagnostics of fungal pathogens using traditional methods can be difficult due to the similarity of their morphological traits, the lack of the ability to study non-culturable genotypes. In this regard, molecular detection methods based on polymerase chain reaction (PCR) were used in the study, which allow specific detection of any microorganisms. Analysis of the species composition of pathogenic fungi of Fusarium, Penicillium and Aspergillus genera in the genotypes of some vegetable crops of local selection was conducted based PCR-assay. The efficiency of molecular technique for the speciesspecific detection of pathogenic fungi that can affect agricultural crops was demonstrated. Molecular diagnostic assessment of the phytosanitary status of seeds of different storage periods was done. Development of some fungal infection during plant ontogenesis using nested-PCR assay was monitored.

FATTY ACID METHYL ESTERS GC/FID ANALYSIS USING ICHIHARA-FUKUBAYASHI MODYFIED METHOD

2025-08-06T10:37:43+00:00

The method for preparing fatty acid methyl esters (FAMEs) from lipids for gas-liquid chromatography, developed by K. Ichihara and Y. Fukubayashi, was optimized as a result of research on the influence of mild (45 ℃, for 14 h) and fast (100 ℃, for 1 h) methanolysismethylation conditions on the FAMEs yield. Based on the minor impact on the final products and the good FAMEs yields, the optimized mild methanolysis/methylation method was applied to eight vegetable oil samples and two types of fish oil dietary supplements. The FAMEs compositions were analyzed by gas chromatography with flame ionization detector (GC/FID). On the recorded chromatograms, 16 types of fatty acids with majority content were identified and their mass fractions were calculated. The modified Ichihara-Fukubayashi method allowed the conversion of ester-bound fatty acids and free acids to FAMEs in a single step. The accuracy, accessibility and convenience of the method, the use of low concentrations of samples and reagents were noted.