Analecta Technica Szegedinensia

The Examination of Apple Shelf Life from Consumer Storage Perspective

Anna Farkas — 2024-10-28

Proper storage and preservation of apples is essential for consumer satisfaction and the efficiency of the food industry. The aim of this research is to investigate in detail the impact of different storage conditions on the physical and chemical properties and shelf life of apples, with particular emphasis on the differences between store and home storage.

In the experiment, commercially available Golden Delicious apples are stored in cold storage at two different temperatures (5°C and 10°C) and known relative humidity (85 RH%) to simulate consumer storage conditions. The study is conducted for 10 weeks, with weekly sampling. The parameters analysed include physical properties such as weight, size, colour and meat firmness, as well as chemical properties such as sugar and acidity. Statistical methods are used to collect and analyse the data and to search for correlations and relationships between the different parameters in order to help consumers to effectively preserve and evaluate the quality of the apples.

Home storage of apples plays an important role in economic processes, as it contributes to reducing food waste and promoting more sustainable food consumption. If consumers are able to store apples properly at home, less fruit is wasted, which reduces food waste.

Petrographic Characterisation and Paleoenvironmental Reconstruction of the Kipala Shales (Central Basin, DRC, Kwilu Province)

Djonive Munene — 2024-10-28

In order to fill the glaring gaps in geological data for the Kipala region, in the Kwilu province of the Democratic Republic of Congo, geological studies were carried out. The results identified four different lithofacies in the study area: dark greasy shale, feldspathic microgres, clayey sandstone and bituminous shale. The petrographic compositions and palaeoenvironmental conditions of the deposit are presented for the first time in this work. From a petrographic point of view, the rock samples analysed differ in the nature of their constituent minerals and/or matrix or cement. Similarly, there is a close relationship between local lake and river sediments. The size and degree of rounding of the clayey sandstones in the rocks studied suggest that they were transported over a long period under strong hydrodynamic conditions.

Investigation the machining of the engineering polymers

Róbert Kovács — 2024-10-28

During the turning process, we have investigated the problems that can arise, such as avoiding the formation of flow
chips, which are eliminated by sawing the workpiece longitudinally. Furthermore, we measured the main cutting forces
acting on the blade and the cutting forces in the feed direction at different feed rates, depths of grip and cutting speeds,
and investigated possible correlations between these.
Chips produced at different cutting parameters and with different materials were investigated. All turning operations
are carried out without emulsion and all other coolants for environmental and other reasons.
The specific cutting resistances have been determined, which are essential for determining good tool utilisation and
also for planning the economics of machining
The aim of this research is to define machining parameters that can be used in practice for the engineering plastics
under investigation, so that the machining of these materials by turning can be made more economical.

Mechanical Properties and Microstructural Characteristics of Steel Pipes after Long-Time Hydrogen Exposure

Nóra Nagy — 2024-10-28

There are three possibilities to transport hydrogen by high pressure pipeline (i) blending hydrogen into the existing natural gas pipeline system, (ii) after checking the integrity, using the natural gas transporting pipeline system to transport hydrogen, (iii) building a new pipeline system to transport pure hydrogen. In all three cases should be known the behaviour of the pipe material and its welded joints influenced under high pressure hydrogen. For this aim pipeline sections made of P355NH base material were investigated without and with hydrogen exposure, where the exposure time was 41 days. Gas metal arc welding and hybrid tungsten arc welding / gas metal arc welding were applied for preparation of the girth weld joints. Tensile, three point bending and hardness tests, furthermore microstructural investigations were performed both on base materials and girth welds of the pipeline sections. The testing results were analysed and compared with each other (base material vs. welded joints, without exposure vs. with exposure) and with limit values can be found in the literature. Conclusions were drawn on the behaviour of the investigated pipe material and its welded joints.

Review and Prospects of Xanthan Application in Water Contaminants Removal

Ida Zahović — 2024-10-28

This review explores the novel perspectives and application of xanthan in the removal of emerging water contaminants. Xanthan is a nontoxic, biocompatible, and biodegradable biopolymer of microbial origin. Industrial production of xanthan is usually conducted by aerobic submerged batch cultivation of the bacterium Xanthomonas campestris ATCC 13951 on the medium containing glucose or sucrose under optimal conditions, and findings of researchers worldwide indicate that xanthan can be successfully biosynthesized on media containing different waste streams, using various Xanthomonas strains. Common application of xanthan is in the food industry as a stabilizer, thickener, and emulsifier because of its high viscosity at lower concentrations and excellent solubility in hot and cold water. The application of xanthan is not only limited to the food and other branches of industry, but also to medicine, biomedical engineering, agriculture, and wastewater treatment. Recent studies have confirmed the excellent photocatalytic activity and emulsifying capacity of xanthan biosynthesized on waste-based media, which offers promising potential for its application in the decontamination of environment. Moreover, the xanthan-based hydrogel has great selectivity for the cationic dye and on the other side, chemically modified xanthan has a great potential as an adsorbent for the removal of metal ions.

Analysis of the Spanwise Effect behind a Cylindrical Body

Bence Molnár — 2024-10-28

The study of the flow around the cylinder is still a focus of research in various aspects. In this case, the flow around an electrically heated cylinder with a diameter Ød=10 mm is investigated at low velocities (mainly in the laminar range). In the literature, the wall temperature Tw is used in many places to characterize such flows. This is usually considered constant, because experimental tests are mainly performed with electrically heated rods of small diameter (max ~2 mm). Since in our case the rod diameter is a multiple of this, the question arises whether the two-dimensional nature of the flow behind the cylinder is preserved. The spanwise effect behind a transversely placed heated cylinder was investigated. The results obtained provide a good basis for designing further measurement options.

Osmotic Treatment of Orange and Pink Sweet Potato-Mass Transfer Rate and Efficiency

Biljana Lončar — 2024-10-28

Sweet potatoes (Ipomoea batatas) are globally cultivated due to its adaptability, high nutritional value, and short growing season, tolerance to high-temperature soils, low fertility, and minimal pest or disease issues, making it a valuable asset to the food industry. Osmotic treatment, a renowned preservation technique requiring mild temperatures and minimal energy, has gained prominence. Over ten years of research at the Faculty of Technology Novi Sad has pioneered the use of sugar beet molasses as an effective osmotic solution for drying different herbs, fruits, vegetables, and meat. This study specifically focused on osmotically treating samples of pink and orange sweet potatoes in sugar beet molasses (80% w/w) to explore the influence of solution temperatures (20°C, 35°C, and 50°C) and osmotic treatment durations (1h, 3h, and 5h) on mass transfer rate and treatment efficiency. The Principal Component Analysis (PCA) and color correlation analysis were employed to illustrate the connections between different sweet potato samples. Findings indicate that the mass transfer rate peaks at the onset of the process. Particularly with the highest temperature after 1h of osmotic treatment The highest values for RWL and RSG (13.33±0.02, 1.85±0.04 and 11.51±0.02, accordingly) were obtained for both orange ((15.19±0.08 g/(gi.s.w.·s)·10⁵and 4.53±0.06 g/(gi.s.w.·s)·10⁵) and pink sweet potato ((9.91±0.02 g/(gi.s.w.·s)·10⁵ and 3.78±0.04 g/(gi.s.w.·s)·10⁵), respectively. Notably, diffusion is most rapid within the initial three hours, suggesting potential reductions in processing time aligned with these results.

The Influence of the Type and Concentration of Plasticizer on the Properties of Biopolymer Films based on Wild Flax (Camelina Sativa)

Danijela Šuput — 2024-10-28

The development of biodegradable packaging materials using naturally occurring, renewable biopolymers has gained attraction due to consumer demand for high-quality products and concerns about environmental waste problems. However, the inferior mechanical properties and low water resistance of packaging materials based on natural polymers pose a significant obstacle to their wider use. One of the ways to improve the properties of biopolymer-based packaging materials is the addition of plasticizers during their synthesis. In this work, the influence of the type and concentration of plasticizer on the properties of new biopolymer films based on wild flax (Camelina sativa) was investigated. Camelina sativa oil cake (CSoC) remains after edible oil cold pressing as a by-product. One of the possibilities for its valorization is the synthesis of biopolymer materials. During the synthesis, different plasticizers - glycerol and polyethylene glycol 400 - were added in different concentrations - 20%-60%. The obtained CSoC-based biopolymer films were analyzed for the following properties: Moisture content, solubility, thickness, tensile strength, elongation at break, and water vapor permeability. The results obtained showed significant differences when different plasticizers were applied at different concentrations. The biopolymer film with optimal properties was obtained by adding glycerol at a concentration of 40%.

Effects of Foot Orthoses and Kinesio Tape on Spatiotemporal and Kinetic Gait Parameters during Running in Individuals with Flatfoot

Hairong Chen — 2024-10-28

Flatfoot is a common condition that influences gait and can cause discomfort for patients under higher loaded condition, such as running. Identifying the most effective treatment necessitates a comprehensive analysis of each therapy's impact on gait. Our research delved into the effects of Foot Orthosis and Kinesio Tape on the spatiotemporal and kinetic aspects of gait in individuals with flatfoot during running. Twenty female rearfoot strike runners with flatfoot participated in the running tasks at 3.3±5% m/s on the Zebris Medical GmbH treadmill. Gait data were collected under three conditions: shoe (A), shoe with Foot Orthoses (B), and shoe with Kinesio Tape (C). A one-way repeated measures ANOVA was employed to analyzed the gait parameters during the stance phase. Under conditions B and C, the foot rotation angle significantly decreased compared to condition A. Additionally, in condition B, it was significantly lower than in condition C. Under conditions B and C, the maximum force and pressure of forefoot significantly increased, whereas it in the midfoot significantly decreased, relative to condition A. Foot Orthosis and Kinesio Tape both effectively diminished peak midfoot pressure during running. Additionally, Foot Orthosis surpassed Kinesio Tape in enhancing foot stability and function throughout the running. These findings offered valuable insights for the selection of intervention measures for patients with flat feet during running.

Developing Excel VBA Functions for the Mathematical Modeling of Three-Dimensional Vectors

Zoltán Fabulya — 2024-10-28

The current computer support for operations involving three-dimensional vectors is insufficient, even in widely used programs like Excel. These programs lack customised features specifically designed for vector operations. However, this limitation can be overcome by using the options provided by Visual Basic for Applications. By creating user functions, we can effectively calculate various results related to the mathematical application of vectors. These functions include determining the magnitude and absolute value of a vector, calculating the angle between two vectors or the cosine of that angle, finding the scalar product and vector product of two vectors, and evaluating the mixed product of three vectors. By incorporating these custom functions into the spreadsheet program, users can easily perform mathematical calculations pertaining to three-dimensional vectors.

Biomechanical Analysis and Modeling of Different Traction Patterns in Adolescent Idiopathic Scoliosis

Qiaolin Zhang — 2024-10-28

Objective: Traction is a valuable treatment for Adolescent idiopathic scoliosis; however, assessing its biomechanical effects, particularly with new methods, presents challenges. This study aims to explore the biomechanics using finite element analysis, with the goal of enhancing safety and effectiveness. Methods: Based on CT images, two different boundary and loads were applied to simulate two traction methods. The effects of these two traction methods on stress and deformation of lumbar vertebral bodies and intervertebral discs were compared. Results: Under two traction methods, the stress was concentrated on the posterior side. Multi-point traction resulted in higher stress and deformation, and concentrated stress on the convex side as well. However, there is some stress concentration on the vertebral arch, which may lead to injury. Conclusion: Compared to longitudinal traction, multi-point traction can better reduce stress on the vertebral bodies and intervertebral discs, focusing the pulling force on the concave side and achieving greater deformation. Multi-point traction might better suit specific patients needing more correction and pressure relief compared to longitudinal traction.

Comparative Analysis of Milling Technologies in Dark and Milk Cocoa Topping Production for Ice Cream

Tijana Popović — 2024-10-28

Chocolate and cocoa toppings are widely used for confectionery products. Toppings used for ice creams contain higher fat content (about 40-60%) to ensure a greater flow to cover the whole product. The dark cocoa topping consists of cocoa and sugar powder distributed in vegetable fat, while cocoa topping with the added 7% non-fat milk fraction is regarded as a milk cocoa topping. This research aimed to determine and compare the impact of the ball mill, and five-roll mill and conching used for the production of dark and milk cocoa toppings regarding the particle size distribution, rheology properties and content of moisture, sucrose, fat and lactose. The obtained results showed that the volume-weighted mean parameter D (4,3) was lower in the samples produced in a ball mill. Additionally, the viscosity, linear and Casson, slightly increased in samples produced in a ball mill except for the milk cocoa topping which had 0.55 fold higher value of linear viscosity compared to the sample produced using a five-roll mill and conching. Regarding the results of NIR spectroscopy, it was found that the samples produced in a ball mill showed higher values of moisture, but lower values of sucrose, lactose and fat.

Risk-taking Factors in a Dynamic Approach

László Csorba — 2024-10-28

The most common definition of risk is quantified by the probability of an adverse event occurring and the value of the adverse consequence. Theoretically, the decision to take a risk can also be based essentially on these two pieces of information. In addition, according to traditional risk-taking models, the perception of risk, the psychological characteristics of the decision-makers and their relevant experience are also important. In the case of mathematical-statistical-psychological models, little emphasis is placed on the fact that risk is in fact the inability to completely control the activity in question. The causes of this incompleteness are based on the shortcomings in the relevant capabilities of the economic agent. Economic agents have different capabilities, so they rarely face the same risks, even for almost identical activities. Just as the requirements and circumstances of the activity are constantly changing, so are the capabilities of the economic agent. Consequently, the size of the capability gap of an economic agent is also constantly changing. This should be taken into account in risk-taking decisions and their revision. The paper attempts to model this dynamic risk-taking mechanism and to show how different risk-taking strategies may be pursued by economic agents in certain baseline situations.