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Primena satelitskih snimaka za daljinsku detekciju pomeranja zemljine kore prisutna je u naučnoj literaturi već više od dve decenije. Analiza je pokazala da takođe postoji mogućnost primene InSAR tehnologije, odnosno interferometrijskog radara sa sintetičkom blendom za ranu detekciju geodinamičkih procesa. Porastom broja javnih i komercijalnih satelita u Zemljinoj orbiti, dostupnost i učestalost prikupljanja potrebnih podataka značajno su porasli poslednjih godina. Sada je moguće prikupiti podatke u vremenskim rasponima od svega nekoliko dana za svaku tačku na površini zemljine kore. Praćenje pomeranja infrastrukturnih objekata tradicionalnim geodetskim metodama je izuzetno skup i neefikasan proces. Sa druge strane, potreba za detekcijom i eventualnom predikcijom i prevencijom geoloških procesa u pojasu putne ili železničke infrastrukture nije upitna. Naučna saznanja u oblasti InSAR tehnologije dostigla su zrelost koja opravdava njenu potencijalnu primenu u infrastrukturi. U okviru ovog rada napravljen je pregled uspešnih primena ove savremene tehnologije u saobraćajnoj infrastrukturi, kao i pregled različitih metoda prostorne i vremenske obrade interferometrijskih podataka. Konačno, izvršena je analiza pomeranja karakterističnih deonica državnih puteva u Srbiji.

The Materials with a negative Poisson’s ratio are recognized as Auxetics materials. Compared to conventional materials it has the counter-intuitive property that during the compression the structure tends to contract and stretch when it expands. These particular attributes identified in the literature have encouraged further research on this topic. The flexible photopolymer resin is used for the test specimens, which have a cylindrical-shell based Auxetics structure. The test specimens are printed on an LCD printer with resin which gives structure ductile properties during the compression test. Using an industry camera the dimensional changes are captured for further research. With Digital Image Correlation method experimental results show different scenarios in varying the dimensions of the structure. Analyzed results give a foundation for future research, giving it a special focus on improving the quality of future tests and giving a perspective of potential applications and manufacturing variations of Auxetics structures.

In this study, the research focuses on tensile PA12 specimens with CAD model dimensions selected according to the ISO 527-2 standard, with bulk dimensions of 170x20x4 mm. The study utilizes a Fuse 1 (FormLabs, Summerville, MA) 3D printer that employs SLS technology. This printer is capable of producing objects with different shapes and dimensions simultaneously, provided that they are printed at a minimum distance of 5 mm apart. The research involves producing two batches of specimens, each differing in printing orientation (i.e., horizontal and vertical). After printing, the specimens are tested using a Shimadzu AGS-X universal testing machine with a capacity of 100 kN to evaluate the mechanical characteristics of the materials. The findings reveal that horizontally printed specimens have a modulus of elasticity about 9.3% higher than the manufacturer's stated value, while vertically printed specimens show an increase of approximately 11.4%. This enhancement is likely due to the thermal and cooling cycles during printing. The difference in modulus of elasticity between the orientations is around 2%, indicating a minor impact on mechanical properties.

This research aims to determine how the orientation and placement of printing impacts the compressive strength of specimens manufactured by Selective Laser Sintering (SLS). The research includes compressive specimens in which the CAD model dimensions are selected according to the ISO 604 standard, and specimen geometry Ø10x20 mm in bulk. All specimen configurations are additively manufactured in two different printing orientations, horizontal and vertical, and printed in the middle and on the edge of the powder bed. All specimens are additively manufactured using Polyamide 12 (PA 12) material on a Fuse 1 device (FormLabs, located in Summerville, MA). Compressive strength testing was carried out using a Shimadzu AGS-X universal testing machine (Shimadzu Corp., Kyoto, Japan).

Razvoj i proširenje mreže auto-puteva spada u red ključnih faktora koji omogućavaju brži ekonomski napredak u nerazvijenim i zemljama u razvoju. Donosioci odluka o velikim kapitalnim projektima, kada razmišljaju da li uopšte ući u izgradnju novog projekta autoputa, svoje odluke prevashodno baziraju na inicijalnim procenama troškova izgradnje i očekivanim koristima od te izgradnje. Međutim, baš u početnim fazama investicionog projekta, prilikom izrade inicijalnih procena troškova, investitori i potencijalni izvođači radova nailaze na brojne izazove. Najveći izazov su vrlo oskudne informacije o karakteristikama budućeg auto-puta i nedostupnost ili mali broj podataka o troškovima prethodno realizovanih projekata, a na osnovu kojih bi se doneli zaključci o očekivanim troškovima realizacije budućih projekata..., The development and expansion of the highway network is one of the key factors that enable faster economic growth in underdeveloped and developing countries. Decision makers for large capital projects, when considering whether to enter or not into construction of a new highway project, primarily base their decisions on initial construction cost estimates and expected benefits from that construction. However, in the initial stages of an investment project, owners and potential contractors encounter numerous challenges when making initial cost estimates. The biggest challenges are very scarce information on the characteristics of the future highway and the unavailability or small amount of data on the costs of previously implemented projects, based on which conclusions could be made about the expected costs of implementing future projects...

Forging, as a type of technological process based on metal forming, is widely used in the modern manufacturing industry. This paper is focused on the utilization of CAE software tools for simulating the forging process of an aluminium piston. The starting point for designing the technological process was a technical drawing of the machined piston. After determining forging tolerances, parting lines, forging angles, radii, and flash land, the forging part and forging dies were designed. The forging process in this particular case encompasses three metal-forming operations: upsetting, final forging, and trimming of the flash. The proposed technological solution was verified using the CAE software tool - QForm through various simulations of material behaviour during the forging process. The analysis included material flow, potential defects, as well as temperature and stress within the workpiece. After making a few adjustments to the forging design and parameters, the optimal solution was presented. Temperature and stress distributions in the best-case scenario were within an acceptable range, while the risk of surface defects and material flow abnormalities was very low. This paper demonstrates that the use of software tools for numerical simulations during the design of the forging technological process provides significant benefits, such as reducing production costs, improving product quality, minimizing scrap, saving time in product development, and reducing the number of required test samples.

Rapid prototyping technology has emerged as one of the most significant technologies that enable the reduction of the product development and production times. The novel low-cost desktop multifunctional machine tool, able to support additive and subtractive manufacturing of symmetrical and asymmetrical cylindrical parts, is presented. The core of the invention is the new concept of the machine tool with a horizontal rotating device chuck (3-axis rotary CNC) as a multifunctional rapid prototyping machine. The specific concept of the machine’s geometry enabled reconfigurability, i.e., the simple change of tools for the unique combination of three production technologies on one desktop machine: milling, laser engraving, and rotary 3D printing. Open-source control infrastructure enables end-user customization and machine upgradeability and achieves cost-effectiveness. Innovative design enables additional technological advantages in the desktop rapid prototyping machine tools domain, such as: 1) the possibility of the production of a single cylindrical part completely in one clamping by using a combination of additive and subtractive manufacturing (which achieves effective use of material, energy, and reduced time consumption, increased productivity, increased accuracy); 2) modularity and the open architecture control structure which allows for upgradeability and further development of the machine according to end-user needs (possibility to add supplementary axes per users’ demands; 3) digital twin technology. MultiProDesk is a valuable production tool for SMEs in various production technologies where it allows users to adopt mass customization concepts and to reach mass personalization production (as a step to Industry 4.0).

A continuous and sufficient supply of top-quality water is imperative for the proper development and survival of bees. Beekeepers often rely on a variety of water containers, each afflicted with numerous shortcomings such as limited capacity, irregular water availability, and subpar sanitation. This analysis aims to investigate the different categories of bee drinkers essential for meeting the water needs of bees. Additionally, we will conduct an in-depth examination of the pros and cons associated with each type of waterer to gain insights into their effectiveness and their impact on bee colonies. Ultimately, we will determine the most suitable waterer for the unique conditions and demands of beekeeping operations.

Simulating the process of NC milling of freeform surfaces is of fundamental importance in computer aided manufacturing (CAM). In order to accurately predict cutting force in sculptured surface machining with ball end mill, tool posture, cutting edge, contact state between cutter, and workpiece are studied. Cutting force prediction is very important to optimize machining parameters, monitor the machining state and to reduce the possibility of tool breakage. In order to predict the cutting force of surface machining with a ball end mill, different materials and geometry of the tool/workpiece are studied. In this paper, the state of the art is presented in the field of force prediction in ball end milling and the advantages of different methods for determining the cutter-workpiece engagement. The research for cutter-workpiece engagement (CWE) under different cutting conditions is mainly divided into three types: solid modeling, discrete representation, and analytical methods. The resulting surface quality after machining with a ball end cutter is of great importance because finished milling is often the last process step determining the functional performance of a component.

In this paper is presented revitalization of the horizontal boring mill machine Stankoimport 2620B using a PLC controller manufactured by Schneider Electric and a DC converter manufactured by SSD Parker. As the machine is of an earlier production date, this method of feederate regulation in today's time is a problem because it is difficult to get the components in order to perform the maintenance or repair of the machine. The old control system was based on the use of electron tubes and an electromechanical amplifier. For this reason, a reconstruction was made using modern components for the control and regulation of the speed of the DC motor for feedrate moving. During the reconstruction, all AC motors and a DC motor with a tachogenerator were retained. All motors are tested and the brush holders was replaced on the DC motor and new brushes were installed. For the new part of the control system, which was built into the old control system, PLC software was developed and written, and new DC motor control hardware was installed. After revitalization, the machine was successfully tested in metal machining and the functionality of the installed components was proven. This revitalization was useful because the control panel on the machine remained the same as original state and it was not needed additional training of machine operator and also the electricity consumption and noise was reduced.

Veliki industrijski razvoj je poslednjih decenija izazvao nekontrolisano iskorišćavanje prirodnih resursa i degradaciju životne sredine, što je dovelo do zabrinutosti društva za posledice koje utiču na stanje životne sredine. Izgradnja putne infrastrukture je jedan od glavnih faktora koji doprinose globalnom zagrevanju u oblasti građevinarstva. Procenjeno je da svaki metar izgrađenog puta godišnje izazove emisiju gasova staklene bašte u iznosu od 14,7 kg CO2ek, gde su faza ekstrakcije i proizvodnja materijala glavni procesi koji doprinose ukupnoj emisiji ugljenika i potrošnji energije. (1) To je razlog zašto izbor materijala za izradu kolovoznih konstrukcija direktno utiče na lokalno zagađenje i degradaciju životne sredine. U ovom radu je razmatrana upotreba bakarne i čelične zgure kao delimične zamene prirodnog agregata u asfaltnim mešavinama i analiziran je životni ciklus kolovoznih konstrukcija, napravljenih od pomenutih mešavina. Eksperimentalna istraživanja su pokazala da upotreba bakarne i čelične zgure u asfaltnim mešavinama dovodi do povećane potrošnje veziva prilikom spravljanja mešavina i do povećavanja transportne mase, što dovodi do povećane potrošnje energije i negativno utiče na globalno zagrevanje i zdravlje ljudi. Međutim, upotreba ovih industrijskih nusproizvoda u asfaltnim mešavinama dovodi do uštede prirodnih agregata i rešava problem deponovanja ovog otpadnog materijala na odlagalištima, što je veoma značajno sa ekološkog aspekta., In recent decades, large-scale industrial development has caused uncontrolled exploitation of natural resources and environmental degradation, which has led to society's concern about the consequences affecting the state of the environment. The construction of road infrastructure is one of the main factors contributing to global warming in the construction industry. It has been estimated that each meter of road constructed annually causes greenhouse gas emissions of 14.7 kg CO2eq, where the extraction phase and material production are the main processes that contribute to the total carbon emissions and energy consumption. (1) This is the reason why the choice of materials for the construction of pavement structures directly affects local pollution and environmental degradation. In this paper, the use of copper and steel slag as a partial replacement of natural aggregate in asphalt mixtures was discussed and the life cycle of pavement structures made from the aforementioned mixtures was analyzed. Experimental research has shown that the use of copper and steel slag in asphalt mixtures leads to increased consumption of binder for preparation of mixtures and to an increase in transport mass, which cause increased energy consumption and negatively affect global warming and human health. However, the use of these industrial by-products in asphalt mixtures leads to the saving of natural aggregates and solves the problem of depositing this waste material in landfills, which is very significant from an environmental point of view.

Osnovni cilj prilikom razvoja novih metoda ispitivanja bitumena je da se odrede karakteristike veziva koje su vezane za ponašanje asfaltnih slojeva u fazi eksplatacije i za nastanak dominantnih oštećenja na fleksibilnim kolovoznim konstrukcijama: kolotraga, pukotina usled zamora i termičkih pukotina. Ova ispitivanja je neophodno sprovesti pri različitim nivoima starenja, koje treba da simulira eksplatacione uslove za bitumen i asfaltne mešavine tokom njihovog životnog veka. U radu je prikazan razvoj specifikacija za ispitivanje putnih i polimer modifikovanih bitumena, kao i savremeni postupci za ispitivanje karakteristika bitumena koji se primenjuju u Sjedinjenim Američkim Državama, u kontekstu unapređenja specifikacija Superpave, kao i u Evropi, pre svega imajući u vidu očekivano novo izdanje standarda EN 14023 koji se odnosi na polimer modifikovane bitumene. Posebno su obrađene metode za karakterizaciju veziva na visokim eksplatacionim temperaturama, kao što su metoda MSCR (Multiple Stress Creep Recovery), razvijena u SAD, i Brza metoda za karakterizaciju bitumena BTSV razvijena u Nemačkoj. Na kraju je dat pregled novouvedenih ispitivanja u okviru predloga specifikacija za polimer modifikovane bitumene.

The ball end cutter is a commonly used tool for rough machining free-form surfaces. This paper presents a procedure for rough machining parts with free-form surfaces on 3-axis machines. To achieve this, a model for predicting cutting forces is developed and implemented in a software solution for automatic technology design. This software solution has been previously tested and described. The procedure enables the optimal utilization of the tool while considering the maximum allowed cutting force for the selected tool diameter. The tool diameter is automatically determined based on the analysis of the surface geometry and is chosen to be smaller or equal to the minimum surface radius. The software solution includes an input of the part CAD model in STL file format and a tool database specific to the machine used. After upgrading the software with new strategies for rough machining, the generated NC code was tested on a CNC machine, and manufacturing was performed within the specified tolerances and surface roughness. The research was conducted at the Department of Production Engineering at the Faculty of Mechanical Engineering in Belgrade, where this topic has been actively studied for many years and is still under development. The described software solution is beneficial as it allows users to operate with minimal knowledge of CAM systems.