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The purpose of this paper is to determine the temperature fields in the workpiece and the tool in the ironing process using an integrated approach that includes laboratory experiments and numerical modelling. An originally developed model device for ironing sheet metal strips, which was previously shaped by U-bending, was used for the experimental research. Thermocouples were installed in the device at the position close to the contact surface with the workpiece. The device was mounted on a hydraulic press that enables maximum ironing speeds of v = 4,17 mm/s. In order to determine the temperature fields at higher ironing speeds, a series of numerical experiments was performed at identical speeds as in the experiments (0,33 mm/s and 4,17 mm/s) and at higher speeds (100 mm/s, 1000 mm/s and 10000 mm/s). Good matches of the experimental and numerical results at lower speeds were obtained, so the numerical estimates at higher speeds were valid for the analysis and conclusions. With the increase of the ironing speed, a trend of temperature increase is evident. The maximum temperature of 166 °C at ironing speed of 10000 mm/s that corresponds to manufacturing of 250 cans per minute is significantly lower than the critical melting temperature of the tin coating.

The deep drawing technology has a significant place in the contemporary industry. Intensive development of the automotive industry contributes a lot to that fact. With development of the new materials of the poorer machinability and with increase of the technological requirements to the higher level, the necessity for complete control of the forming process is increasing as well. There are significant difficulties in realizing any action during the process duration. In present conditions, only two possibilities are at hand: the blank holding force of the variable intensity and drawing beads of the variable height. Both actions require complex control systems. Contemporary technological problems in deep drawing of parts of the complex geometry can be successfully studied experimentally by means of the physical modeling. The physical model of the contact between the flat surfaces has the dominant space at the flange during the deep drawing process of thin sheets. The emphasis is on realizing the nonlinear dependencies of the contact pressure during the process, as one of the possibilities for the process control. The forming process is usually realized in such a way that all the process parameters and conditions (the blank holding force, deformation rate, etc.) are being set prior to the sliding path of the machine. The concrete investigation shows what effects are realized due to the variable intensities of the blank holding force during the deep drawing process. In addition, it is important to define the functional dependencies of the blank holding force. The basic idea is setting the variable pressure in the contact during the sliding process and monitoring the drawing force (the friction force), the friction coefficient, surface roughness of the thin sheet and the tool. Three different materials were applied, two types of lubricants and four versions of the tool's contact elements. The conducted investigations were of the theoretically-experimental chara, REZIME: Tehnologija dubokog izvlačenja zauzima značajno mesto u savremenoj industriji. Intenzivan razvoj automobilske industrije tome veoma doprinosi. Razvojem novih materijala lošije obradivosti i povećanjem tehnoloških zahteva na viši nivo, raste potreba za potpunim upravljanjem procesom oblikovanja. Postoje znatne teškoće u ostvarivanju bilo kakvih dejstava dok proces traje. U sadašnjim uslovima to su samo dve mogućnosti: sila držanja promenljivog intenziteta i zatezna rebra promenljive visine. Oba dejstva zahtevaju složene upravljačke sisteme. Savremena tehnološka problematika dubokog izvlačenja delova složene geometrije može se uspešno eksperimentalno izučavati putem fizičkog modeliranja. Fizički model kontakta između ravnih površina zauzima dominantan prostor na obodu komada pri dubokom izvlačenju tankih limova. Jedna od mogućnosti upravljanja procesom je zadavanje nelinearnih zavisnosti kontaktnog pritiska za vreme njegovog trajanja. Proces oblikovanja se najčešće realizuje tako što se svi parametri i uslovi procesa (sila držanja, brzina deformisanja, i dr.) podešavaju pre početka radnog hoda mašine. Konkretno istraživanje pokazuje kakve efekte ostvaruju promenljivi intenziteti sile držanja za vreme procesa dubokog izvlačenja. Takođe, od bitnog značaja je i definisanje funkcionalnih zavisnosti sile držanja. Osnovna ideja je zadavanje promenljivog pritiska u kontaktu za vreme procesa klizanja i praćenje promene vučne sile (sile trenja), koeficijenta trenja, površinske hrapavosti lima i alata. Primenjena su tri različita materijala, dve vrste maziva i četiri varijante kontaktnih elemenata alata. Sprovedena istraživanja su teorijsko-eksperimentalnog karaktera s težištem na eksperimentu. U prvom delu istraživanja izvodi se teorijska analiza i kritičko sagledavanje dosadašnjih rezultata. Zatim sledi formiranje nelinearnih i linearnih funkcionalnih zavisnosti simultane promene sile držanja (kontaktnog pritiska) tokom procesa, zavisno od hoda uzorka lima. Osobenost

Istraživanja predstavljena u disertaciji imala su za cilj formiranje regresionog modela procesa vakuumske infiltracije u postupku vezivne 3D štampe, radi uspostavljanja analitičke zavisnosti između ključnih tehnoloških parametara infiltracije i mehaničke čvrstoće infiltriranih epruveta. Dizajn eksperimenta i optimizaciju parametara su izvršeni korišćenjem novog postupka dizajna eksperimenta, Definitive Screening Design. U poređenju sa literaturno dostupnim rezultatima zatezne čvrstoće, dobijenim primenom komercijalnih prahova, vezivnih sredstava i epoksidnih infiltranata, optimizovanim parametrima vakuum infiltracije zatezna čvrstoća epruveta je poboljšana za 23%., The research presented in this thesis was aimed at forming a regression model of the vacuum-assisted infiltration process in binder printing technology (3DP). The goal was to establish analytical relationship between key infiltration technological parameters and tensile strength of infiltrated parts. The design of experiment and optimization of the infiltration process was performed using a novel Definitive Screening Design method. Compared to the literature results which pertain to tensile strength obtained using commercial powders, binders, and epoxy infiltrates, the optimized model of vacuum-assisted infiltration yielded an increase of 23% in tensile strength.

Pasivni bežični LC senzori projektovani su u tehnologiji štampanih kola (PCB) i u tehnologiji nisko-temperaturno pečene keramike (LTCC). Predstavljena su tri tipa LC senzora izrađenih na PCB-u u jednoslojnoj i dvoslojnoj štampi. Takođe su prikazana i dva tipa LC senzora izrađenih u LTCC tehnologiji. Karakterizacija senzora je izvršena u laboratorijskim uslovima a za testiranje korišćeni su građevinska opeka i siporeks blok kao jedni od najčešće korišćenih materijala u građevinskoj industriji za zidane objekte., Passive LC wireless sensors are designed in technology printed circuit boards (PCB) and the technology of Low Temperature Co-Fired Ceramics (LTCC). Presented are three types of LC sensors made on the PCB in the monolayer and bilayer press. It also presents two types of LC sensors manufactured in LTCC technology. Characterization of the sensor is carried out in the laboratory for testing were used building bricks and aerated concrete block as one of the most commonly used materials in the construction industry.

The study was conducted to evaluate the effect of anticoagulant therapy in women with thrombophilia and to detect the possible differences among carriers of mutations (factor V [FV] Leiden and FIIG20210) and those with natural anticoagulant deficiency. The 4-year prospective investigation included 85 pregnant women, with a history of recurrent fetal loss (RFL). They were treated with prophylactic doses of low-molecular-weight heparin (nadroparin) starting from 6 to 8 weeks of gestation. Pregnancy outcomes were evaluated based on the thrombophilia type. Carriers of thrombophilic mutations had a live birth rate of 93%, compared to 41.6% for women with natural anticoagulant deficiencies. Significant differences between the groups were also observed for intrauterine fetal death, intrauterine growth restriction, and postpartum thrombosis. The optimal therapy for women with natural anticoagulant deficiency and RFL remains unclear and future prospective study with a large number of patients is required to determine the best treatment for these severe thrombophilic conditions.

Uvod. Venski tromboembolizam je multifaktorijalna bolest koja nastaje u interakciji genetskog i stečenog faktora rizika. Nakon bolesti koronarnih krvnih sudova i moždanog udara, najčešći je razlog kardiovaskularne smrti ili onesposobljenosti. Materijal i metode. Sa ciljem da se utvrde kliničke krakteristike prvog venskog tromboembolizma, u studiju je uključeno 447 žena mlađih od 45 i 174 žene starije od 45 godina, koje su testirane na prisustvo trombofilije u periodu 1998-2012. godine. Rezultati. Proksimalna duboka venska tromboza češće je zastupljena kod mladih žena, dok je distalna učestalija u grupi starijih. Najčešći faktor rizika za trombozu, koji je utvrđen kod 49,8% mladih žena je trudnoća i stanje posle porođaja, dok se kod 25,2% tromboza razvila bez jasno prepoznatljivog faktora rizika. U grupi starijih žena, tromboza nastaje kod 38,5% bez faktora rizika, dok je malignitet kao najznačajniji faktor rizika utvrđen kod 23%. Prisustvo trombofilije zabeleženo je kod 48,7% mladih, odnosno kod 28,7% starijih žena, p lt 0,001. Razlika se beleži i u odnosu na ponavljane venske tromboze koje su zabeležene kod 26,3% mladih, odnosno kod 17,8% starijih žena, p = 0,03. Zaključak. Kod mladih žena se razvijaju klinički teže venske tromboze nego kod starijih. Urođeni faktor rizika otkriven je kod skoro polovine mladih ispitanica, odnosno kod svake četvrte starije žene. Sa izuzetkom faktora V Leiden mutacije ostali tipovi urođene trombofilije su gotovo zanemarljivi u grupi starijih žena. Stoga je testiranje na prisustvo trombofilije u slučaju prve tromboze, u potpunosti opravdano samo kod mlađih žena., Introduction. Venous thromboembolism is a multifactorial disease defined by multiple interactions between genetic and acquired risk factors. After coronary heart disease and stroke, venous thromboembolism is the most common cause of cardiovascular death and disability. Material and Methods. In order to investigate the clinical characteristics of first venous thromboembolism, 447 women younger than 45 and 174 over 45 years of age with confirmed venous thromboembolism, who had been tested for the presence of thrombophilia in the period 1998-2012, were included in the study. Results. Proximal deep vein thrombosis occurred most often among young women, while distal deep vein thrombosis was the most frequent in the older group. The most common reported risk for venous thromboembolism observed in 49.8% of the young women was pregnancy and puerperium, while 25.2% of them developed venous thromboembolism without any obvious cause. Among women over the age of 45, venous thromboembolism developed without an obvious cause in 38.5%, while malignant disease was identified as the most important risk factor in 23% of them. Thrombophilia was observed in 48.7% of the young women in comparison to 28.7% of the older ones (p lt 0.0001). As for venous thromboembolism recurrence, it developed in 26.3% of young women and 17.8% of the older ones (p = 0.03). Conclusion. Younger women developed more severe forms of thrombosis than the older ones. Inherited risk factor for thrombosis was detected in almost half of all young women, and in every fourth elderly women. With the exception of factor V Leiden mutation, other types of congenital thrombophilia are almost negligible among older women. Therefore, thrombophilia testing in case of first thrombosis is fully justified only in young women.

Predmet ovog rada su teorijsko-eksperimentalna istraživanja projektovanja složenih tehničkih sistema na primeru realizacije mehatroničkog sistema za izradu specijalno oblikovanih žičanih profila (skraćeno, linija MSŽ). Proizvodi koji se dobijaju na liniji MSŽ su specijalni žičani profili poprečnog preseka trapeznog oblika, prstenasto savijeni na određenom koraku radi dalje montaže u finalni proizvod, strogih zahteva kvaliteta (potrebna tvrdoća, uske tolerancije mera oblika i dimenzija, itd). Profili se izrađuju od žice kružnog poprečnog preseka, prečnika Ø2÷5 mm, uglavnom od kvalitetnih nerđajućih čelika u normalizovanom stanju. Dobijeni žičani profili koriste se za formiranje tzv. pukotinastih sita (u svetu poznata kao Looped Wedge Wire Screens)., The paper is focusing theoretical and experimental research of design of complex technical systems on the example of realization of mechatronic system for production of specially-designed wire profile (abbreviated MSZ). Products obtained on the MSZ are specially designed wire profiles wedge shaped and looped on a certain step for further assembly into final products having strict quality requirements (high hardness, tight tolerances of the dimensions shape and size, etc.). Profiles are fabricated from circular cross section wire with diameter of Ø2-5 mm, mainly high-quality stainless steel in the normalized condition. Obtained wire profiles are used for production of socalled Looped Wedge Wire Screens. System complexity enables all challenges of the mechatronic systems design to be shown, to perform all the necessary analysis both analytical and experimental, and to define mechatronic system with best characteristics by the synthesis of relevant data. Along with prototype realization an integrated design methodology of complex technical systems has been developed. Specific requirements are defined and many problems of theoretical and practical character have been solved. Certain experimental measurements were performed to verify obtained analytical results. Process parameters and particular solutions for specific segments of the system are defined by a modeling, simulation and analysis.