International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This study aims to present the practical application of the Dentistry 4.0 concept based on obtaining data on the patient’s intraoral situation and bone base using CBCT, processing them into a digital model, creating a digital twin, and then developing an intraprocedural navigation procedure through a dedicated surgical guide and then designing and manufacturing, using 3D printing, implantprosthetic restorations. The study describes the results of the author’s work, indicating the engineering aspects of implant prosthetic treatment based on the description of cases related to the reconstruction of single missing teeth using dental implants implanted in the case of difficult anatomical conditions of the bone base and/or adjacent teeth, with a discussion of the material selection methodology, technological and structural design, using additive manufacturing.
The technology for the design, manufacture and application of implant-prosthetic restorations developed by the author, preceded by a fully navigated implantation procedure of dental screw implants, illustrates in practice the full application of the Dentistry 4.0 concept, where the latest technologies, including primarily computer-aided design and computer-aided CAD/CAM manufacturing, the use of a digital twin, supporting surgical procedures through the use of templates navigating the operator’s actions and additive manufacturing allow for a radical increase in the availability of implant-prosthetic solutions for patients with difficult anatomical conditions, both due to a limited bone base and anomalies of the anatomy of adjacent teeth. Thanks to the latest technology, not only is it possible to perform this type of procedure, but it is also possible to perform the procedure in a short time, with minimal interference in the patient’s tissues and ensuring the optimal shape of the prosthetic restoration itself.

The paper deals with an operating photovoltaic plant in Bulgaria. The wide application of photоvoltaic plants in the energy system is known. At the same time, subject matters about their normal functioning are fundamental. The goal of the paper set is to analyze data from the operation of a photovoltaic power plant , which is ultimately related to improving its behavior. Relevant conclusions have been dоne.

The integration of small-scale photovoltaic power systems into residential and commercial buildings is rapidly gaining popularity. Despite the original design specification for these systems to function solely on local networks or without internet connectivity, they are often linked to installers’ or building managers’ monitoring systems. The substantial surge in demand and deployment of photovoltaic systems necessitates an examination of their susceptibility to a broad spectrum of threats, encompassing both physical and cyber-attacks. This analysis endeavours to identify the components of these systems and evaluate the associated security vulnerabilities. Additionally, it will include a practical demonstration of selected attacks on a representative system to illustrate potential threats. The analysis will culminate in a summary of recommended security protocols aimed at fortifying the security and robustness of PV systems.

This paper provides a comprehensive overview of the preparation and deployment of secure Over-The-Air (OTA) updates for embedded devices. In the era of intelligent devices, the need for remotely updating software and firmware has become increasingly prevalent. This paper discusses the principles of OTA updates, focusing on the various types used in the field of embedded devices and the complications that need to be resolved for a successful process. Furthermore, it delves into the theoretical description of OTA updates, security mechanisms, and practical implementation. The paper also highlights the main benefits of OTA updates, such as convenience, security, scalability, reduced maintenance costs, and improved performance. Additionally, it addresses the challenges and issues associated with OTA updates, including update reliability, security risks, compatibility, network propagation, and integrity and warranty implications. Overall, this paper serves as a valuable resource for understanding the complexities and importance of OTA updates in the realm of embedded devices.

Nowadays, many structures should be inspected, analyzed, and repaired. This is a complex and expensive process that also includes predictive analytics to prevent possible construction failures.
One of the most used predictive analytics applications involves extracting necessary metadata from images and videos to evaluate the condition of real-world systems and recommend measures to sustain these systems. Image analysis is not a new concept – many solutions have been used for several decades.
The current paper mainly focuses on OpenAI-based capabilities to implement Image Analysis and Cognitive Digital Twins and proposes faster, cheaper implementation and more adaptive approaches to offering predictive analysis for constructions.
ChatGPT (Chat Generative Pre-Trained Transformer) is one of the trending technologies in modern Artificial Intelligence (AI), and experts in this area expect to have a very high impact on the industry shortly.
One of the latest versions – GPT-4 Turbo with Vision, developed by OpenAI, is a significant multimodal model (LMM) capable of interpreting images and providing text-based answers to queries regarding those images. It combines capabilities in natural language processing and visual comprehension.
The proposed approach considers using OpenAI LLM and Digital Twins for three different aspects of predictive analysis for Construction: image analysis, case decomposition, and creation of self-adaptive models to find possible trends to compromise structures and offer preventive actions. This research compares traditional methods for inspection and repair of Construction, including the time required for predictive analysis, the correctness of the proposed actions, and the cost of the methodology.

Unmanned underwater vehicles (UUVs) are gaining traction in various fields, from oceanographic research to defence applications, due to their versatility and autonomy. This preliminary study explores the integration of Internet of Things (IoT) technology and beamforming techniques to enhance the sensory capabilities of UUVs. The study delves into the evolving landscape of sensory systems, emphasising the incorporation of IoT to enable seamless data exchange, real-time monitoring and adaptive decision making. It also examines the use of beamforming techniques in directional sonar sensing, highlighting their role in improving target detection, localisation and tracking capabilities in underwater environments. By synthesising current research and technological trends, this review provides valuable insights into the synergistic integration of IoT and beamforming techniques to enhance the capabilities of UUV sensor systems for diverse applications.

Paper presents experimental work focused on the application of the separating agent-lubricant SafetyLube 7815 on the surface of the tested samples: ground surface; polished surface; surface of the samples textured by laser in the mode stochastic texture mode. Duplex PVD coatings nACRo4, AlXN3 and AlTiN G were deposited on the surface. The aim of the experimental work was to approximate the breakin conditions of a new or renovated mould part for high pressure casting of aluminium alloys. The release agent-lubricant SafetyLube 7815 was applied to the surface of the specimens by dispersive spraying. The method of measuring the contact contact angle measurement, the influence of the finishing operations of the mould part surface on the surface wettability by contact angle measurement.

International trade is still heavily reliant on oceangoing vessels and the noxious bunker fuel that feeds most ships’ massive diesel engines. Although shipping contributes relatively small shares of GHG emissions per unit of transport work, without further action, emissions from the sector would continue to increase. Therefore the maritime community and ship-owning companies are attempting to achieve “green shipping”. The revolutionary technology to use the wind for assisting the ship’ propulsion is one of best steps for decarbonisation of shipping. This innovative technology could bring considerable reducing fuel consumption and cost savings, improving the ships efficiency as well. There are different ways to utilize the wind power, as several kinds of rotors, sails, kites, etc, some of them already installed on commercial ships, some are still dreams. The aim of this paper is to present the basic essence of wind-assisted propulsion and the environmental impact of its use.

The main challenge in the design of tissue substitutes is still the realization of a customized implant with good interface properties without any risk of subsequent inflammation. The application of laser bases methods to development of constructs with improved biomimetic properties is an excellent strategy owing to the possibility of fabricating complex scaffolds with hybrid porosities. The micro/nano porosity is an important condition for cell viability and tissue ingrowth. An interconnected pore structure will permit inwards diffusion of oxygen and nutrients and outwards diffusion of waste products from the scaffold. Ceramic materials are difficult to process due to their brittleness and chemical inertness, but they can be patterned by high energy ultrafast laser radiation, generating specific isotropic and anisotropic micro/nano topographies. The aim of this study is to be able to develop functional, porous biomaterials surface with improved porosity, biocompatibility, biodegradation rate and multifunctionality by employing Freeze Foaming/Hybrid Shaping technology and high precision ultra-short laser processing method. An important advantage of this approach is that the mechanical properties of treated surfaces remain the same after the treatment, which modifies roughness and hydrophilicity and therefore affects the response of cells and bacteria.

The paper presents the applicability of gamma irradiation for the degradation of mycotoxins ochratoxin A, zearalenone and deoxynivalenol in wheat flour. The experiment was carried out by contamination of wheat flour samples with mixture of the mycotoxins and their gamma irradiaton with doses of 5 kGy, 10 kGy and 20 kGy using industrial gamma irradiation facility BULGAMMA. The concentrations of the mycotoxins before and after the radiation processing were measured by HPLC. The results showed that the application of a dose of 10 kGy resulted in incomplete decomposition of the investigated mycotoxins: 12 % of deoxynivalenol, 13 % of ochratoxin A and 37 % of zearalenone. The decomposition of the investigated mycotoxins in wheat flour achieved after gamma irradiation with a dose of 20 kGy was found to increase in the following order: ochratoxin A (48 %) > zearalenone (66 %) > deoxynivalenol (97 %).

This paper presents an investigation of innovative nanostructured semiconductive materials, focusing on dichalcogenides of transition metals, particularly WS2. The properties of WS2 in the context of its application in sensor technology and highlight the anticipated advantages of nanostructured disulfides compared to bulk semiconductor materials are discussed in the introduction. We propose a model sensor element based on the nanostructured disulfide WS2 and introduce a technological method utilizing electron beam lithography (EBL) for its preparation. The paper details the processes involved in preparing the resist masking layer using EBL, the metallization of the interdigital electrode (IDE) with contacts and important EBL characteristics such as a contrast curve, dependence of the linewidth on the exposure dose, and the line edge roughness.

The article reviews the chemical and active compounds of the lyophilized essential oil of Thymus vulgaris L. and its preservation qualities. Thymus vulgaris is a medicinal plant belonging to the Lamiaceae family, with a long history of use for its therapeutic properties. The essential oil of T. vulgaris has been widely studied for its antimicrobial, antioxidant, and anti-inflammatory activities. The amounts and types of chemical compounds can vary depending on the genetic differences or environmental conditions of the plant materials. The primary components of the essential oil responsible for most of its biological effects include thymol, carvacrol, and p-cymene. The essential oil of T. vulgaris has been reported to exhibit a wide range of pharmacological activities, including antimicrobial, antioxidant, anti-inflammatory, antifungal, and antiviral activities. In recent years, there has been increasing interest in the use of T. vulgaris essential oil as a natural preservative in food products.