Studia Universitatis Babeș-Bolyai Engineering

Leveraging smart contracts for enhanced traceability and security in bank transactions on a blockchain platform

Obamehinti Adeolu SEUN, Adekunle ELUDIRE, Araoluwa Simileolu FILANI — Mon, 28 Oct 2024 00:00:00 +0000

Traceability of transaction have been an issue facing the financial institution for a long time. The banks are the actors who have overall responsibility for financial transaction, thus placing them in a position of responsibility for realizing the traceability demands. The bank has the coordinating role in financial transfers as well as performing tasks during transaction. Due to lack of traceability, a lot of fraudulent activities go on without being detected one of which is the issue of fake alert system, where money could assume to be transferred to a recipient account and yet not reflect in the account balance. It needs to be established that financial traceability is a problem that requires solution. In other to address these, blockchain technology which is a noble disruptive technology that is tamperproof, secure and transparent and store hash value of data is the most viable way of addressing the challenge of traceability of financial transactions.

Computational algorithm for evaluating gravitational and inertial loads acting on an industrial robot for palletizing operations

Roxana-Mariana NECHITA, Cozmin CRISTOIU, Mihai MĂRGĂRITESCU — Mon, 28 Oct 2024 00:00:00 +0000

This paper introduces a computational algorithm designed to calculate the gravitational and inertial loads affecting a four-axis numerically controlled (NC) industrial robot (IR) used in palletizing operations. The methodology includes the development of precise calculation models that account for the dynamic interactions between the robot’s mechanical components and its operational environment. These models enable the accurate determination of load distributions and stresses on each axis, which are critical for optimizing the robot’s performance and ensuring reliable operation under various loading conditions. The algorithm can be applied to the optimization and refinement of existing robotic systems, as well as to the design of new robots tailored for specific industrial applications.

Predictive control of an induction machine drive system for field-weakening regime

Elena SELIM, Ion VONCILĂ — Mon, 28 Oct 2024 00:00:00 +0000

In this paper is studied the model predictive control (MPC) of an induction machine (IM) drive for wakening applications. The control structure is implemented in Matlab software. The predictive control law is based on finite set combinations imposed by the two-level inverter topology. The study developed for field-wakening regime shows that the speed tracking objective remains stable despite stator resistance variation. Also, the load torque disturbance rejection is efficiently done to evaluate un unrated parameter. Thus, the operation of the IM drive with MPC law is robust on the sensitivity of parameters of the model.

Performance of 32kb/s ADPCM for data transmission

Muhanned AL-RAWI — Mon, 28 Oct 2024 00:00:00 +0000

This study introduces a brand-new modified QAM modem that transmits data at a rate of 14.4 kbps over a 32 kbps Adaptive Differential Pulse Code Modulation (ADPCM) channel. This modified QAM modem’s goal is to lessen the nonlinear distortion that ADPCM introduces. The effectiveness of ADPCM is investigated using modified and regular QAM modems with various constellations. The simulation findings demonstrate that ADPCM performs better when using a customized QAM modem than when using a normal QAM modem. Additionally, a circular constellation performs better than a rectangular one.

Determining the optimum severity of damage using model performance analysis methods

Santatra Mitsinjo RANDRIANARISOA, Gilbert-Rainer GILLICH — Mon, 28 Oct 2024 00:00:00 +0000

In this work, we have considered a cantilever beam with a rectangular plastic cross-section, reinforced by four wire reinforcements made of ductile Iron. It was studied using numerical resolution based on theoretical formulae and then simulated using Solidworks software. A comparison of the results on the frequency ratios between the theoretical and numerical by Solidworks models gave a low error of 1.389% with a high correlation coefficient of around 0.959. Then, two top reinforcements inside the beam were cut in order to study the behavior of the intact beam and the damaged beam. Using the simulation results, we found an accurate damage severity using a mathematical method based on error deviation indicators or Model Performance Analysis (MPA).

Dynamic behavior of a simply supported circular plate

Ionela HAREA, Zeno-Iosif PRAISACH — Mon, 28 Oct 2024 00:00:00 +0000

The paper presents a study regarding the dynamics behavior of thin circular plate simply supported with a relation obtained analytically and the graphic representation of the modal shapes. The modal shapes are obtained using Bessel functions and their graphic representation are compared with Finite Element Method (FEM) by using modal analysis. For the analyzed case, the first 70 eigenvalues and natural frequencies are calculated.

Reverse engineering of a toothed gear

Antonio-Patrik NEDELCU, Cristian TUFISI — Mon, 28 Oct 2024 00:00:00 +0000

With the rapid development of modern industry, the need for spare parts has increased. Most mechanical systems have transmission components which are composed of toothed gears. In most cases, the manufacturer of the spare part does not exist on the market and the need to reproduce the failed part needs to be met. Usually, toothed gears are obtained using special cutting machines, like Gleason, Lees-Bradner, and Pfauter. To be able to reproduce the part by using a common manufacturing process, the current paper presents a RE method for obtaining the 3D geometry of a toothed gear in the scope of machining the part using a CNC 3-axis mill. CAD software and 3D scanning technology is used to recreate the gear’s 3D model and ensure accurate dimensions for the gear teeth, including tooth spacing, depth, and angle.

Simulation of a serial topology robot operation using the 3DEXPERIENCE platform

Razvan-George OLINGHERU, Adrian-Bogdan OLARIU, Calin-Octavian MICLOSINA — Mon, 28 Oct 2024 00:00:00 +0000

The paper presents the assembling of a 3D model serial topology robot, the definition of kinematical joints of the guiding device mechanism and the simulation of robot operation, using the 3DEXPERIENCE platform. In the end, there are presented different positions of the robot during simulation.

FocusedDFT: A DFT implementation for vibration-based structural damage detection

Petar PRVULOVIĆ — Mon, 28 Oct 2024 00:00:00 +0000

This paper introduces focusedDFT, a novel Discrete Fourier Transform (DFT) implementation optimized for short signals with low frequency components, particularly where a single frequency component is of interest. The results suggest focusedDFT as a viable and efficient solution for vibration-based damage detection methods, offering improved execution times compared to traditional DFT approaches.

The effect of the signal initial phase on the amplitudes of a DFT spectrum

Daniela Giorgiana BURTEA, Nicoleta GILLICH, Gilbert-Rainer GILLICH — Mon, 28 Oct 2024 00:00:00 +0000

Knowing the amplitudes in a spectrum calculated using the Discrete Fourier Transform (DFT) algorithm is essential for precisely estimating the frequencies of a real-valued signal. Since the amplitudes are affected by the signal's initial phase, it is crucial to consider this aspect when estimating the signal frequencies. This paper presents the initial signal phase's effect on the values calculated for the real and imaginary parts and the magnitudes in the DFT of a real-valued signal. Analyzing the evolution of the amplitudes with the initial phase for a complete cycle for the initial phase, we found that the values in the magnitude DFT are subject to minor alteration, while the values of the real and imaginary parts of the DFT are strongly affected by the initial phase.

Dynamic behavior of a Warren truss beam upon loosening of a bolt in a truss node

Dan Alexandru PÎRȘAN — Mon, 28 Oct 2024 00:00:00 +0000

The present work aims to show our practical achievements made in the laboratory of the UBB Resita faculty, where on Warren truss hinged at both ends, we studied the negative impact of loosening a bolt in a truss node that has them on natural frequency. Based on the bolt tightening, the specimen had three different states: healthy state, damage state I, and damage state II.

Eigenvalues of a continuous beam with two spans

Patric-Timotei STAN, Zeno-Iosif PRAISACH — Mon, 28 Oct 2024 00:00:00 +0000

Continuous beams can be found in various engineering applications. The dynamic behavior of continuous beams is strongly influenced by the location of the intermediate support. The paper presents the determination of the frequency equation depending on the location of the intermediate support for a continuous beam with two openings for the case that this support can be placed in any position along the length of the beam. Finally, the obtained curves of the eigenvalues for the first six vibration modes are represented.

The influence of stiffness on the dynamic behavior of a PCB enclosure

Razvan-George OLINGHERU, Adrian-Bogdan OLARIU, Zeno-Iosif PRAISACH — Mon, 28 Oct 2024 00:00:00 +0000

The paper presents the modification of the first 6 natural frequencies for a PCB case where the material quality was modified from Ultradur B4300 G6 material in AlSi12Cu1 aluminum alloy. Following the change in the quality of the materials, the natural frequency of the 1^st vibration mode changed from 164 Hz to 378 Hz, as a consequence of the change in the modulus of elasticity, respectively the stiffness.

Analysis of methods of hardening and restoration of worn parts

Iskakova DINARA, Kasenov ASYLBEK, Magellan DARIYA, Zoltan-Iosif KORKA — Mon, 28 Oct 2024 00:00:00 +0000

The restoration of worn parts is an important aspect in the field of machine repair and maintenance of machinery. It allows you to significantly reduce repair costs and is a priority issue in the development of a machine maintenance and repair system. The main causes of performance loss products are abrasive wear, fatigue breakdowns, corrosion and other types of destruction. When choosing a recovery method, the type of coupling, types of friction and operating conditions of the machines are important factors. An increase in wear resistance can be achieved by changing the chemical composition of the material, mechanical influences and the application of wear-resistant coatings.

Organization of truck maintenance

Bulbul BULBUL, Nurbolat SEMBAYEV, Zoltan-Iosif KORKA — Mon, 28 Oct 2024 00:00:00 +0000

Increased maintenance performance is able to contribute in growing the profitability of a transport company. Maintenance produces financial costs as well as losses in terms of availability. While the financial costs are a direct economic loss, availability losses causes indirectly an economic loss. Therefore, proper maintenance of trucks leads to high availability, thus increasing short-term profit of a transport company. This paper deals with the development production and technological tasks development of innovative system of vehicle operating in the Republic of Kazakhstan, due to the centralized specialized technical repair organizations or auto services in the context of the specific modifications of trucks together with the manufacturers. It presents a methodology for assessing the operational efficiency of contemporary commercial vehicles from different brands and manufacturers for which there isn’t yet a legal framework.

Aspects from the Museum of the Faculty of Engineering in Reșita

Eugen RĂDUCA, Cornel HAȚIEGAN, Petrișor Dorel ȚĂRAN, Roberta RĂDUCA — Mon, 28 Oct 2024 00:00:00 +0000

The work presents elements of the professional activity carried out within the institution of higher technical education in Reșita, since its establishment (year 1971) and in the following 50 years of existence. The framework that was chosen is that of the establishment of a museum. Some significant devices and equipment worked with in the students’ laboratory works, two stands made by students in the graduation projects, and two laboratory works made by students in some profile disciplines are presented.

An assessment of the impact of commercial land use on residential housing. A case study of Auchi, Edo State

Mon, 28 Oct 2024 00:00:00 +0000

Auchi’s strategic location as a commercial hub has led to a significant expansion of its economy, resulting in a complex interplay between residential living conditions and economic development. The goal of this study was to determine how commercial activity affects residential housing in Auchi in order to raise the standard of housing there. In order to raise Auchi’s housing quality, this study aims to evaluate how commercial activity affects residential housing. In order to accomplish this goal, the following goals were taken into account: figuring out why residential housing in Auchi was converted to commercial use; figuring out what mixed-use housing Auchi has; figuring out what commercial activity is currently taking place on the city’s stock of residential housing; figuring out how these commercial activities affect Auchi’s residential housing; and figuring out the overall effects of commercial activity on Auchi’s residential housing. 155 questionnaires were distributed to various study areas’ quarters as part of a quantitative research methodology. The basic percentage method was employed to analyze the gathered data. The research findings indicate that although commercial activities have created job opportunities and drawn many individuals and families to Auchi, there are drawbacks as well. Firstly, there is an increasing demand for space, which results in the conversion of residential properties into commercial establishments. This reduces the supply of residential housing for locals, causing a shortage and an increase in housing prices. Based on the research’s findings, the following recommendations were made: the government should enact laws regulating property prices and rentals to ensure that they stay within the reach of locals; collaborate with private developers to construct affordable housing units in Auchi in order to alleviate the city’s housing scarcity; enforce laws governing noise pollution in order to reduce disturbances caused by commercial activity in residential areas; and promote mixed-use development in Auchi, which enables locals to live close to places of employment while preserving their ability to balance their personal and professional lives.

Development and evaluation of a COOI24m pelletizer

Mon, 28 Oct 2024 00:00:00 +0000

It is essential to formulate appropriate feeding pellets with the required nutrient compositions for poultry animals to meet the growing demand for protein through the provision of eggs and meat. Forming the required feed concentrates into pellet-mash requires a pelletizing machine, which is, in most cases, very expensive for the local farmers due to the high foreign exchange rate. Based on this, the study focuses on the development of a simple and affordable pelletizing machine from locally sourced materials. The machine consists of a frame, hopper, die roller, pelletizer, and internal combustion (5.5 hp), and it was run at 950, 600, and 450 revolutions per minute. The formation and discharge of pellets from the machine increased with the pelletizing efficiency (Pe) of 70.3% to 84.6% at a moisture content (MC) of 15.8% to 27.1%, and the Pe decreased at a moisture content above 29.0%. Also, the drying temperature (DT) has a significant effect on the pellet moisture content (MC) and bulk density at P > 0.05. The effects of weather conditions on pellets produced using the COOI24m pelletizer were assessed in this study. The analysis showed that changes in weather conditions had an insignificant effect on the quality and properties of the pellets. The machine is highly recommended for use by small-scale livestock farmers for the local production of pellet-mash of different compositions because of its affordability, ease of use, and high working efficiency.

Development and calibration of a solar-powered egg incubator

Mon, 28 Oct 2024 00:00:00 +0000

This study evaluated the effects of various climatic variables on the efficiency of a solar-powered egg incubator. Results showed that generated incubation temperature (GIT) and relative humidity (GIRH) all significantly impacted the incubator’s performance. Low temperatures negatively affected egg embryonic formation and hatching rates, while high humidity levels resulted in poor egg quality. Additionally, it demonstrated that the incubator could be kept at the desired temperature of 34–38 ^oC and relative humidity of 56–86% for high efficiency. The study also discovered that more solar radiation resulted in more reliable and effective temperature control inside the incubator. The findings of this study offer significant contributions to the enhancement of solar-powered egg incubator designs and the optimisation of their efficiency under diverse climate scenarios.

Estimation of consumptive water use for Watermelon in Auchi, Nigeria

Mon, 28 Oct 2024 00:00:00 +0000

This study aims to estimate the consumptive water use (CWU) for watermelon production in Auchi, Edo State, Nigeria. The research was conducted over a period of eight months (March–October) and used data collected from the watermelon field at the Demonstration and Research Farm of Auchi Polytechnic, Auchi. The result of the experiment revealed the estimation of CWU and watermelon water requirements (CWR) of 175.9 mm and 195 mm for the 62-day (August to October) vegetation stage of watermelon, with a CROPWAT projected harvest on November 20, 2022. The finding also revealed that the mean annual consumptive water use for watermelon production was 520.7 mm. The mean seasonal water use for watermelon production was higher in the dry season (March to June, 488.7mm) than in the wet season (July to October, 390.6mm). However, based on this harvest date, the model predicted irrigation requirements of 23.1 mm and 59.4 mm in October and November. Additionally, this study offers proof that management strategies for water use efficiency and irrigation scheduling can dramatically lower water losses and boost efficiency. The findings of this study can be applied to the Auchi region’s water management decision-making procedures as well as to help watermelon farmers reduce their water consumption levels while maintaining output.

Robotic assembly – mobile platform for construction field

Cosmin PREDA, Robert-Marian BLEOTU — Mon, 28 Oct 2024 00:00:00 +0000

Construction sites often involve the manual transportation of heavy objects, posing risks to workers’ safety and efficiency. In this paper, it was proposed a design, development, and evaluation of a service robot specifically created for carrying heavy objects in the construction field. The robot is equipped with robust locomotion capabilities, intelligent perception systems, and efficient control mechanisms to navigate through complex environments and handle various types of loads. It was presented the technical design of the robot, including its hardware components, sensing modalities, and software architecture. Furthermore, it was discussed the experimental validation of the robot’s performance in real-world construction scenarios, highlighting its effectiveness in improving productivity, reducing labor costs, and enhancing workplace safety. Through this research, the aim is to demonstrate the potential of service robots as valuable assets in the construction industry, paving the way for future advancements in robotic assistance technologies.