Localization aims to provide the best estimate of the robot pose. It is a crucial algorithm in every robotics application, since its output directly determines the inputs of the robot to be controlled in its configuration space. In real world of engineering, the robot dynamics related measurements are subject to both uncertainties and disturbances. These error sources yield unreliable inferences of the robot state, which inherently result in wrong consensus about the appropriate control strategy to be applied. This outcome may drive the system out of stability and damage both the physical system and its environment. The localization algorithm captures the uncertainties with probabilistic approaches. Namely, the measurement processes are modelled along with their unreliability, moreover, the synergy of multiple information sources is formulated with the aim to calculate the most probable estimate of the robot pose. In essence, this algorithm is composed of two main parts, i.e., first the dynamics of the system is derived, and the corresponding uncertainties are initially predicted, next the additional sensor information is incorporated in the algorithm to refine the posterior estimate. This approach provides the state-of-the-art solution for the derivation of mobile robot poses in real applications.

Widely used robot systems have a rigid base structure that limits the interaction with their environment. Due to the inflexible attachment points, conventional robotic structures can only manipulate objects with their special gripping system. It can be difficult for these systems to grasp objects with different shapes, handle complex surfaces or navigating in a heavily crowded environment. Many of the species observed in nature, like octopuses are able to perform complex sequences of movements using their soft-structured limbs, which are made up entirely of muscle and connective tissue. Researchers have been inspired to design and build robots based on these soft biological systems. Thanks to the soft structure and high degree of freedom, these soft robots can be used for tasks that would be extremely difficult to perform with traditional robot manipulators. This article discusses the capabilities and usability of soft robots, reviews the state of the art, and outlines the challenges in designing, modelling, manufacturing, and controlling.

Alzheimer's disease (AD) is a progressive irreversible neurodegenerative disease in the hippocampus and cortex regions of the brain and is the most common cause of dementia in the elderly population among 40 million cases worldwide today, it is thought that this number will exceed up to 100 million by 2050. The disease is characterized by symptoms of memory loss, difficulty in speaking, decision making, learning, problem solving, and impaired perception of time and orientation. In its pathogenesis, the amyloid beta (Aβ) senile plaques accumulation in the extracellular synaptic spaces of the neurocortex, the formation of intracellular hyperphosphorylated tau protein deposition and neurofibrillary tangles (NFY) are important and triggered neurodegeneration mainly affects cognitive behavior and memory. Phenolic compounds are organic compounds containing a benzene ring to which one or more hydroxyl groups are attached. Studies have shown that regular consumption of polyphenols reduces the risk of developing neurodegenerative diseases. Studies have reported that polyphenols inhibit Aβ production and accumulation processes by interacting with different forms of amyloid structure. In this study, polyphenols and their therapeutic properties against AD will be discussed extensively.

Today there is a great deal of controversy over the operation of inertial propulsion drives (IPD), as they challenge the laws of Newtonian mechanics. Starting with the last decades of the previous century, many devices that use the centrifugal force to generate linear propulsion were patented. Regrettably, whether we are talking about the initial, or the most recent attempts, only a few of these systems passed the patent stage and were involved for practical applications. The aim of this paper is to present an IPD, developed by the authors, which uses for generating linear motion the kinetic energy of several masses, placed in the articulation points of the links of a chain drive. The masses placed equidistantly along the half-length of the chain perform a complex movement, consisting of the specific displacement of the chain elements and a rotation around an axis, that is parallel to the line which joins the centres of the chain wheels. After deducting the equations of the geometric coordinates of the masses, the total propulsion force was computed. The obtained results are supporting the ability of the IPD to generate propulsive force and linear motion.

Fault detection techniques based on vibration measurement are implemented to identify in an early stage failures appearing in gear transmissions. Condition monitoring indicators (CMI), like: Root Mean Square (RMS), Crest Factor, Kurtosis, FMO, FM4, Energy ratio, Energy operator, NA4 or NB4, are used to estimate the level of gear faults such as pitting, cracks, spalling, scuffing or scoring. However, in is multitude of indicators, the question that arises is: which CMI is the most sensitive in estimating the severity of defects? Thus, this paper presents an extensive comparison between the before mentioned indicators computed from vibration signals collected on four pinions with different pitting grades, created by artificial means. The pinions where incorporated in a single helical gearbox and the tests were performed on an open-energy test rig at three different input speeds. This comparative study assesses the receptivity of different condition monitoring indicators towards gear pitting failure. We concluded that all the involved indicators are responsive and sensitive to fault diagnosis, even in low speed operating conditions.

Over functioning time, structures can be affected by multiple types of damages caused by fatigue, improper production methods, or exceeding loads. The current paper describes a method for evaluating the severity of transverse cracks that are present in beam-like structures based on changes in the natural frequencies. Because the presence of damage has a negative impact on the energy that a beam can store in the affected section, it is possible to find the influence of the crack on any other position along the beam, considering the stored normalized energy in that location. The technique is based on a mathematical relationship that provides the exact solution to the frequency changes of the bending vibration modes, considering two terms. The first term is related to the tensile energy stored in the beam, and the second term considers the increase of flexibility due to cracks, for this reason, damage assessment is performed in two stages; first, the location of the crack is found and then an assessment of its severity is performed. In this study, the aim is to test the developed method for estimating the severity of transverse cracks for different sections and lengths of beams.

Biopolymer films have an increasing share in the packaging material sector due to a number of advantages: availability, cheapness, easy processing, degradability, etc. On the other hand, numerous methods have been developed to optimize their unfavorable properties (weaker mechanical characteristics, hydrophilicity, etc.). This paper examines the influence of the synthesis method on starch-gelatin films properties. The starch-gelatin film was synthesized in a ratio 1:1 as a composite film (C). The second sample was obtained by gelatin film lamination on starch film (L). Plain starch film was used as a control (0). Mechanical, structural and physico-chemical properties of importance for the application of packaging materials were tested on the obtained samples. All the obtained biopolymer films were transparent and easy to handle. FTIR spectroscopy identified all characteristic groups and bonds formed in composite and laminated films. The results showed a significant contribution of gelatin in the developed biopolymer films compared to the control sample. Gelatin incorporated as a film component or as a separate layer improved mechanical properties and water solubility. Slight differences were observed between composite and laminated films because the effect of the method of added gelatin is minimal compared to the sample without the addition of gelatin.

Real beams have non-ideal boundary conditions and it is necessary to use new models to determine the real modal parameters. Models that use ideal conditions do not fully reflect reality and can lead to unsatisfactory description of the dynamic behavior. The hinged – hinged boundary conditions, which is in the focus of the paper, are not analyzed as a single beam, but as a continuous beam with three spans, free at the ends. The continuous beam with three spans is analyzed for cases in which the intermediate supports can occupy any position along the length of the beam, by an analytical solution of the problem, with the example of cases when the intermediate supports are located very close at the free ends of the continuous beam, thus simulating the real case for an hinged beam at both ends; the situation in which the intermediate supports are very close to one of the ends of the beam, thus simulating the real case of the clamped beam, with an imperfect clamped end; and the situation in which the intermediate supports are very close located anywhere on the beam length, thus simulating the hypothetic case with a continuous beam free at the ends and fix on the hinged supports. The analytic results are compared with numerical results by using finite elements method.

Calculations typically performed on a calculator or computer show the result as a decimal fraction if it is not an integer. It would be easier to interpret the result if a value could be expressed with integers and operations, such as the root subtraction operation. This article shows how this can be done with a developed algorithm in Microsoft Excel, which recognizes the most famous irrational numbers and displays them in text form together with the character of the operation sign. For example, “5√3/2” is given for 4.330127019. It is also useful to display irrational numbers with integers because only an infinite number of decimal places in a decimal fraction could show the exact value, and that is not possible. So, the developed algorithm can display a more interpretable and accurate form of the irrational number. In addition to the results that can be written as square roots, the algorithm is capable of displaying irrational numbers that can be expressed as the number Pi, using the π character. The Excel algorithm which was implemented in Visual Basic for Applications shows all rational numbers as the quotient of two integers that are relative primes.

Food preservation technologies are continuously renewed area because of industrial and customer needs, social transformation, environmentally friendly processing and climate change. The shelf life of perishable food products must be extended with different technologies, for example using green methods like the edible coating (EC). EC is made from different biopolymers (chitosan, alginate, gelatine, agar), the effect can increase using plant extracts. This study examined the effect of chitosan EC, chitosan EC+thyme essential oil (EO); effect of alginate EC, alginate EC+thyme EO on fresh chicken breast having artificial contamination with Escherichia coli; Enterococcus faecalis, that the EC can extend the shelf life. The organoleptic quality of baked treated chicken breast was also established. Based on the result both EC can decrease the cell number (with 1-3 log CFU/g) on treated chicken breast and this antimicrobial effect was enhanced with thyme essential oil (3.2 μl/ml concentration). There was significant differences (p<0.05) between the two edible coatings. Alginate had better preservation effect, than chitosan. However, the thyme EO could increase the antimicrobial activity of chitosan in higher values, than the effect of alginate EC. In this experiment, E. faecalis was more sensitive to treatment than E. coli. In conclusion, the edible coating can be used as an alternative preservation technique and combined with essential oils can extend the shelf life of chicken breast fillet.

Under the context of reserve depletion, recovering rare earth elements (REEs) from secondary resources is essential which assists to strengthen the circular economy. Contaminated biomass growing from brownfield lands is a potential material for REE recovery. However, prior to the extraction stage, polluted plants need to be lessened to a manageable volume. In this study, contaminated biomass gathered from an abandoned mining area was combusted in a pilot-scale boiler, while solid residuals from different positions in the burning system were collected and analyzed. Higher REE concentration in the ash samples compared to that in the woody biomass indicates the efficiency of the combustion process from the metal enrichment point of view. The significant metal concentration in the solid remains is an advantage for the following step of extraction to reclaim REEs. It was concluded that the concentration of REEs in bottom ash is greater than in the other solid residuals. That indicates that the volatility of rare earth minerals is limited during biomass incineration.

This paper’s goal is to introduce the third step of the EFOP-3.6.1-16-2016-00014. project on the Faculty of Engineering, University of Szeged. In this period the production technology of composite material was chosen and a fatigue test machine was developed and tested. The paper shortly describes the composite materials and summarizes the theory of fatigue than it presents the process of the development with several prototypes of fatigue test machine, some of which were manufactured and tested. Initially a shaker played the key role in the first two conceptions and finally a crank mechanism became as the best solution. The main solved problems during the development were selection of bearings and solving the partly dynamic balancing of the moving parts.

Based on the domestic and international market trends of the last decades, it can be stated that the number and turnover of web stores, internet commerce is growing dynamically from year to year. The aim of our research is to explore the effective, proven customer acquisition methods of modern web stores. As part of this, the subject of our literature research was to explore the popular advertising platforms for web stores and their basic marketing principles and their optimal structure based on them. In our professional research, on the one hand, we explored through structured interviews what methods and communication are considered effective by the three webshops competing and selling in the different markets based on their experiences. On the other hand, we examined the shopping habits and preferences of consumers in the form of a questionnaire. The information obtained in this way can be crucial in planning the marketing strategy for any existing or new web store. We have found that one of the most important attributes in acquiring customers is reliability. From the beginning, you should strive for positive customer reviews as well as regular value creation proficiency must be demonstrated through content production, with which the business can build a committed community.

In an attempt to provide a more flexible means of achieving friction stir welding (FSW) of Aluminum without the use of expensive FSW machine tool, which are not readily available. This study developed a mobile fixture system (MFS) for FSW on a Vertical milling Machine Tool (VMMT). A conceptual design of a fixture system with a moving work table, which provides for transverse feed (movement) of the workpieces during FSW, was generated. The detailed design of the components of the MFS was done using existing mechanical design formulae. Subsequently, the design was fabricated and evaluated. An ATmega 328P Arduino Uno microcontroller was used to design a control system to automate the MFS worktable movement. Results revealed that the MFS worked smoothly during FSW of AA 1100 materials. The efficiency of its motion accuracy was estimated as 87.2%. Also, the trend of the tensile strength and the hardness value as well as the joint efficiencies of the AA 1100 weldments produced using the developed MFS agreed with existing studies. The MFS can be used for FSW of Aluminum materials on VMMT as well as on pillar drilling machine tool.

This article describes the process of creating the conceptual and logical model of a journal database. To efficiently extract the information from the articles published in the journal so far, the idea of creating a database has emerged. To create a database, it is recommended to design a high-level conceptual model and convert that into a logical data model. The benefit of the thoughtful design is that it shows the structure of the database in an easily comprehensible form. The entity-relationship model is a fast and efficient way to create the conceptual model and it can be easily converted to a relational database model, which is a logical model. The initial version of the entity-relationship model of the journal database had one entity type, 25 attributes, and no relationship. The final version contained three entity types, 39 attributes, and three relationships. This final conceptual model was converted to a logical model, the relational model. The result was ten tables to store entity data with 22 different fields and another three tables to ensure the relationships between the tables. The developed model can be created in a relational database manager and is suitable for serving information needs related to the journal.

Because our infrastructure is aging and approaching the end of its intended functioning time, the detection of damage or loosening of joints is a topic of high importance in structural health monitoring. The most desired way to assess the health of engineering structures during operation is to use non-destructive vibration-based methods that can offer a global evaluation of the structure’s integrity. A comparison of using different modal data for training feedforward backpropagation neural networks for detecting transverse damages in beam-like structures that can also be affected by imperfect boundary conditions is presented in the current paper. The different RFS, RFSmin, and DLC training datasets are generated by applying an analytical method, previously developed by our research team, that uses a known relation, based on the modal curvature, severity estimation of the transverse crack, and the estimated severity for the weak clamping. The obtained dataset values are employed for training three feedforward backpropagation neural networks that will be used to locate transverse cracks in cantilever beams and detect if the structure is affected by weak clamping. The output from the three ANN models is compared by plotting the calculated error for each case.

Almost a third of Earth’s freshwater resources are used by municipalities, agriculture and industries and therefore very large quantities of wastewater are generated and discharged into surface water or groundwater. If discharged inadequately and without previous treatment, wastewater can cause chemical pollution, affect aquatic life as well as human health and have a negative impact on the environment. An emerging technology for wastewater treatment is the membrane separation process due to the low cost, the use of ambient temperature, the low energy consumption compared to other traditional techniques, and the high selectivity of different separation mechanisms with compact design. In this study, ultrafiltration (UF) technique was investigated to treat wastewater with different organic loads. The effects of the stirring and a three-dimensional (3D) printed spacer, integrated into the UF cell were analyzed on the permeate fluxes, membrane rejections of turbidity, conductivity and chemical oxygen demand (COD).