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Дисертација се бави креирањем напредног адаптивног модела краткорочне прогнозе вредности временских серија у паметним инфраструктурним мрежама. Појаве које модел прогнозира односе се пре свега на потрошњу ресурса као што су електрична енергија, природни гас и вода. Модел користи постојеће методе машинског учења, које унапређује како у погледу тачности прогнозе тако и у погледу перформанси. Примарни допринос дисертације је унапређење постојећих техника машинског учења коришћењем предложеног модела.Основа модела је оптимизација избора узорка који користе методе машинског учења у поступку прогнозе. Узорак се односи на дане из историјске базе података. Узорак је репрезентативнији што су дани из узорка сличнији прогнозираном дану. Сличност дана се одређује на основу релевантних фактора сличности. Модел је адаптиван у смислу могућности прилагођавања утицаја и додавања нових фактора сличности.Утицај појединачних фактора сличности оптимизује се метахеуристички, коришћењем генетског алгоритма. У извршавању генетског алгоритма у адаптивном моделу прогнозе уочени су проблеми, који су описани а затим и решени увођењем иновативних техника који унапређују конвергенцију, а последично и тачност коначних резултата прогнозе.Модел поседује могућност континуалног унапређења кроз прилагођавање промењеним календарским и временским околностима. Ова адаптивност омогућена је кроз механизам извршавања генетског алгоритма на дневном и кварталном нивоу, чиме се краткорочно и дугорочно оптимизује утицај фактора сличности.Модел је такође прилагођен специјалним данима – празницима и другим данима чији профили потрошње одступају у односу на стандардне дане. Предложеним решењем у моделу специјални дани се препознају и за њих се извршава прогноза коришћењем посебног алгоритма којим се препознају и примењују специфична правила понашања потрошње.Верификација модела извршена је на две студије случаја. Једна студија случаја односи се на краткорочну прогнозу потрошње електричне енергије у преносној мрежи електроенергетског система за подручје Србије. Друга студија случаја односи се на краткорочну прогнозу потрошње природног гаса у дистрибутивној мрежи за један регион у Холандији., Disertacija se bavi kreiranjem naprednog adaptivnog modela kratkoročne prognoze vrednosti vremenskih serija u pametnim infrastrukturnim mrežama. Pojave koje model prognozira odnose se pre svega na potrošnju resursa kao što su električna energija, prirodni gas i voda. Model koristi postojeće metode mašinskog učenja, koje unapređuje kako u pogledu tačnosti prognoze tako i u pogledu performansi. Primarni doprinos disertacije je unapređenje postojećih tehnika mašinskog učenja korišćenjem predloženog modela.Osnova modela je optimizacija izbora uzorka koji koriste metode mašinskog učenja u postupku prognoze. Uzorak se odnosi na dane iz istorijske baze podataka. Uzorak je reprezentativniji što su dani iz uzorka sličniji prognoziranom danu. Sličnost dana se određuje na osnovu relevantnih faktora sličnosti. Model je adaptivan u smislu mogućnosti prilagođavanja uticaja i dodavanja novih faktora sličnosti.Uticaj pojedinačnih faktora sličnosti optimizuje se metaheuristički, korišćenjem genetskog algoritma. U izvršavanju genetskog algoritma u adaptivnom modelu prognoze uočeni su problemi, koji su opisani a zatim i rešeni uvođenjem inovativnih tehnika koji unapređuju konvergenciju, a posledično i tačnost konačnih rezultata prognoze.Model poseduje mogućnost kontinualnog unapređenja kroz prilagođavanje promenjenim kalendarskim i vremenskim okolnostima. Ova adaptivnost omogućena je kroz mehanizam izvršavanja genetskog algoritma na dnevnom i kvartalnom nivou, čime se kratkoročno i dugoročno optimizuje uticaj faktora sličnosti.Model je takođe prilagođen specijalnim danima – praznicima i drugim danima čiji profili potrošnje odstupaju u odnosu na standardne dane. Predloženim rešenjem u modelu specijalni dani se prepoznaju i za njih se izvršava prognoza korišćenjem posebnog algoritma kojim se prepoznaju i primenjuju specifična pravila ponašanja potrošnje.Verifikacija modela izvršena je na dve studije slučaja. Jedna studija slučaja odnosi se na kratkoročnu prognozu potrošnje električne energije u prenosnoj mreži elektroenergetskog sistema za područje Srbije. Druga studija slučaja odnosi se na kratkoročnu prognozu potrošnje prirodnog gasa u distributivnoj mreži za jedan region u Holandiji., А topic of this dissertation is creating an advanced adaptive model of a short-term forecast of time series values in smart infrastructure grids. The primal phenomena that the model predicts are the consumption of resources such as electricity, natural gas, and water. The model uses existing machine learning methods, improved both in terms of forecast accuracy and in terms of performance. The primary contribution of the dissertation is the improvement of existing machine learning techniques using the proposed model.The basis of the model is the optimization of the selection of samples used by machine learning methods in the forecasting process. The sample refers to days from a historical database. The sample optimization is improved by the increase of the similarity of days from the sample. The similarity of the day is determined by relevant similarity factors. The model is adaptive in terms of adjusting the impact of similarity factors and adding new similarity factors.The influence of individual similarity factors is optimized by the metaheuristics, using a genetic algorithm. The execution of the genetic algorithm in the adaptive model of the forecast deals with problems noticed in this work. The detected issues are described and then solved by introducing innovative techniques that improve convergence, and consequently, the accuracy of the final results of the forecast.The model has the possibility of continuous improvement through adaptation to changed calendar and weather circumstances. This adaptability is enabled through the mechanism of execution of the genetic algorithm on a daily and quarterly level, which optimizes the influence of similarity factors in the short and long term.The model is also adapted to special days - holidays and other consumption profiles that deviate from standard days. The proposed solution recognizes special days and executes a specific forecast by a special algorithm that identifies and applies specific rules of consumption behavior on special days.Model verification was performed on two case studies. The first one refers to the short-term load forecast in the transmission system utility in Serbia. The second case study concerns a short-term forecast of natural gas consumption in the distribution network for a region in the Netherlands.

Geotermalna energija predstavlja jedan od najvažnijih, ali istovremeno i slabo iskorišćenih resursa. Postoji potencijal i mogućnost za eksploataciju geotermalne vode na skoro celoj teritoriji AP Vojvodine. Geotermalna energija se veoma malo koristi i pored toga što po raspoloživim potencijalima spadamo u područja sa bogatijim izvorima. Geotermalna energija može da se koristi u agrobiznisu za zagrevanje zaštićenog prostora, stajskih objekata, domaćinstava, ribnjaka, objekata za proizvodnju, preradu, sušenje, dehidraciju, obradu i čuvanje voća, povrća, cveća, gljiva, za navodnjavanje, balneološke svrhe, sportsko-rekrativne 4 namene i u agroekoturizmu. Primena geotermalne energije za grejanje u poljoprivredi može da dovede do povećanja prinosa, kao i do smanjenja operativnih troškova, posebno u hladnijim predelima. Primena geotermalne energije ima izuzetan značaj u organskoj poljoprivrednoj proizvodnji, s obzirom da je jedan od principa korišćenje obnovljivih izvora energije. Zagrevanje putem geotermalne energije dovešće do redukcije potrošnje fosilnih goriva i pada cene ostalih energenata. Geotermalna energija se u prehrambenoj industriji koristi za sušenje, isparavanje, pranje i održavanje higijene, pasterizaciju mleka, preradu mesa i ribe, sterilizaciju opreme. Sušenje voća, povrća i ribe predstavlja jednu od najšire korišćenih oblasti primene geotermalne energije u prehrambenoj industriji. Koristi se za rasvetu, hlađenje i napajanje pumpi, kompresora, transportera, ventilatora, mašina za sečenje mesa, za obradu, pakovanje i preradu vode. Predmet istraživanja je zastupljenost geotermalne energije i ocena njene energetske i ekonomske efikasnosti u agrobiznisu AP Vojvodine. Cilj istraživanja je da se utvrdi energetski potencijal, odnosno nivo i mogućnost korišćenja geotermalne energije u agrobiznisu Vojvodine, kao i da se predstave ekonomski i ekološki efekti. U istraživanju se primenjuje kombinacija kvantitativno-kvalitativnih metoda, indukcija i dedukcija, analiza i sinteza, apstrakcija i generalizacija, metod deskripcije, statistički metod, komparativna analiza i dr. Primeniće se metod posmatranja sa učestvovanjem. Koristiće se i metod studije slučaja i desk-research metod. Rezultati istraživanja pokazuju da Republika Srbija ima veliki potencijal geotermalnih izvora (preko 100 MW/m2), iako je on mnogo veći, ako se posmatra proizvodnja hrane, električne energije i dr. Republika Srbija raspolaže s 360 izvorišta termalnih i termomineralnih voda, od kojih je samo 10 % iskorišćeno. Na teritoriji Republike Srbije postoje važna izvorišta geotermalnih voda (više od 80 geotermalnih izvora i bušotina ukupne toplotne snage oko 120 MW). Ukupne rezerve kojima Republika Srbija raspolaže jesu značajne, ali rezerve geotermalne energije nisu iskorišćene u dovoljnoj meri. One iznose oko 220 MW toplotne snage, a instalirana snaga svih kapaciteta, koji eksploatišu geotermalnu energiju iznosi oko 90 MW i koriste se u najvećoj meri za balneološko-rekreativne potrebe. 5 AP Vojvodina obiluje velikim bogatstvom geotermalnih izvora. U periodu 1969-1996. godine u AP Vojvodini načinjene su 72 bušotine, a u periodu od 1997. do 2008. godine izbušeno je još 6 bušotina. Ukupna toplotna snaga hidrotermalnih bušotina iznosi prema podacima "NIS Naftagas" iz 2005. godine za 54 hidrotermalne bušotine - 72,579 kW. Uzroci minimalnog korišćenja nisu u tehničkim rešenjima i tehnologiji korišćenja, već u nedostatku finansijskih sredstava, znanja i projekata. Nedovoljna integrisanost naučnih i proizvodnih organizacija, nedostatak toplotnih pumpi, relativno veća početna ulaganja, izostanak stimulativnih mera finansijske podrške i poreske politike negativno utiče na korišćenje geotermalne energije. Stavljanje u funkciju postojećih bušotina zahteva da se uradi konkretan tehno-ekonomski program svih instalacija, rekonstrukcije i popravke, razgovor sa ugovornim korisnicima i iznalaženje novih korisnika i investitora. Korišćenje geotermalne vode u proizvodnji Tilapije i Afričkog soma eksperimentalno je potvrdilo da je moguće uspešno gajiti ove vrste riba u našim uslovima. Dosadašnji rezultati pokazuju da direktno grejanje vode u ribnjacima, korišćenjem različitih energenata, zbog visokih cena nije ekonomski održivo, pa se korišćenje geotermalne energije nameće kao ekonomično rešenje. Geotermalna energija može biti veoma korisna u organskoj poljoprivredi, s obzirom da je jedan od principa korišćenje obnovljivih izvora energije. U agrobiznisu na području AP Vojvodine, korišćenje geotermalne energije skoro da i nije zastupljeno. Potencijal geotermalnih izvora nije u celini iskorišćen, ni sa aspekta turističke tražnje. Raspoložive termomineralne vode u AP Vojvodini pružaju više mogućnosti za razvoj postojećih banja i izgradnju novih banja. Geotermalna energija je veliki potencijal za dugoročni, sigurni razvoj održive poljoprivredne proizvodnje i prehrambene industrije, kao i drugih delatnosti. Takođe, geotermalna energija je svojevrstan odgovor na klimatske promene, nestabilne i rastuće cene konvencionalnih goriva, koja poskupljuju proces poslovanja. Cena korišćenja geotermalnih postrojenja je značajno niža od cene sistema za korišćenje konvencionalnih 6 energenata. Ekonomska analiza, koja uvažava najnovije smernice ekoloških zahteva, neophodnosti bušenja i opremanja bušotine, pokazuje da su bušotine iznad 40 oC i jakog izliva oko 60 m3/h rentabilne, pod uslovom da je potrošač sposoban koristiti ceo potencijal bušotine preko 6000 ha/god. Cene geotermalne energije su niže od mnogih drugih energenata. Visoki početni troškovi, rizik od istražnog bušenja, neujednačena politika subvencija i tražnja govore da je geotermalna energija procenjena, kao najjeftiniji izvor energije 2019. godine. Studije o uporednim troškovima različitih izvora energije pokazuju da je geotermalna energija pristupačan izvor energije i da je cena povoljnija u odnosu na druge tehnologije (osim energije iz malih hidroelektrana), koje su trenutno dostupne. Na području naselja Kupinovo od 1982-1985. godine izvršena su opsežna istraživanja, radi sagledavanja opravdanosti ulaganja u eksploataciju geotermalnih izvora u agrobiznisu, balneologiji i u sportsko-rekrativne namene. Najperspektivniji prostor za dobijanje termalne vode prema proceni, predstavlja potez istočno od Kupinova, u pravcu sela Progara, duž leve obale Save. Na području Kupinova napravljene su dve hidrotermalne bušotine, Kup-1/H i Kup-2/H. Finansiranje realizacije bušenja i istraživanja projekata izvršio je NIS-Naftagas iz Novog Sada. Bušotine su pokazale izvanredne rezultate. Predstavnici sela predložili su da se geotermalna enerija iskoristi za potrebe postojećeg toplog kupatila. Nedostatak finansijskih sredstava uticao je da se realizacija projekta odloži. Bušotina je konzervisana, ali se može brzo dekonzervirati i privesti nameri eksploatacije u agrobiznisu. Imajući u vidu da su pomenute bušotine konzervirane, one bi se uz mala ulaganja mogle osposobiti za eksploataciju i zagrevanje staklenika, koji bi se podigli u neposrednoj blizini. To je najekonomičnije rešenje, pod uslovm da je udaljenost plastenika do 2 km. Povoljna lokacija za iskorišćavanje geotermalne vode nalazi se severno od Starog Bečeja (Medenjača i Veliki Rit) i severozapadno od Novog Bečeja (Ljutovo - Veliki Rit). To bi bile optimalne lokacije za bušenje novih bušotina, imajući u vidu zahteve za efikasnom i ekonomičnom stakleničkom proizvodnjom. Geotermalna voda u Kupinovu se u skladu sa svojim karakteristikama 7 može koristiti i kao pijaća, dok je sa vodom u Bečeju drugačiji slučaj. Ova voda ima povećane količine rastvorenih mineralnih materija (4 g/l), rastvorene i slobodne gasove (uglavnom metan) i srednje je agresivna prema metalima. Ima veće zahteve u tehnološkom procesu i deponovanju posle iskorišćenja, a njeno korišćenje bi moglo biti u energetske svrhe. Ukoliko se pri oceni mogućnosti geotermalnog ležišta u Bečeju krene od parametara dobijenih na bušotini Bč-2/H, mogli bismo zaključiti da se sa jednom takvom bušotinom može zagrevati 2-4 ha pod staklenikom. Izvršena je kompleksna analiza termomineralne vode bušotine u Inđiji - Inđ-3/H. U skladu sa mišljenjem Medicinskog fakulteta, voda sadrži više parametara u nedozvoljenim količinama, pa se ne može koristiti kao pijaća voda. Po fizičko-hemijskim karakteristikama termomineralna voda se može koristiti kao aditivno sredstvo lečenja u oblasti medicinske rehabilitacije, isključivo kupanjem. Geotermalni potencijal u AP Vojvodini nedovoljno je iskorišćen, pa je vlada Vojvodine odlučila da pruži podršku geotermalnim projektima. S obzirom da raspolažemo sa značajnim izvorištima geotermalne energije, imamo potencijal da njenim većim korišćenjem unapredimo poljoprivredu, akvakulturu, životnu sredinu, prehrambenu industriju, agroekoturizam, balneologiju i druge proizvodne i uslužne delatnosti. Stimulisaće se posebno staklenička i plastenička proizvodnja. Nedovoljna je iskorišćenost raspoložive geotermalne energije u agrobiznisu AP Vojvodine, iako je dokazano da je geotermalna energija ekonomičnija u odnosu na druge izvore energije. Potrebno je da država podstiče naučno-istraživački rad u oblasti proizvodnje termalnih pumpi, da daje veće subvencije za korišćenje obnovljivih izvora energije, da podstiče korišćenje već postojećih bušotina, koje su zapostavljene, kao i bušenje novih. Republika Srbija je zavisna od uvoza energenata, pa se nameće kao nužno hitno pristupiti izradi strategije, koja će pridavati značaj većem korišćenju geotermalne i ostalih izvora energije. Geothermal energy is one of the most important, but at the same time, low-utilized resources. There is a potential and possibility for the exploitation of geothermal water on almost the whole territory of AP Vojvodina. Geothermal energy is very little used despite the fact that, according to available potentials, we are in areas with richer sources. Geothermal energy can be used in agribusiness for heating protected areas, farm buildings, households, ponds, facilities for production, processing, drying, dehydration, processing and storage of fruits, vegetables, flowers, mushrooms, irrigation, balneological purposes, sports and recreational purposes in agroecotourism. The application of 10 geothermal energy for heating in agriculture can lead to an increase in yields, as well as to a reduction in operating costs, especially in colder areas. The application of geothermal energy is of great importance in organic agricultural production, since one of the principles is the use of renewable energy sources. Heating through geothermal energy will lead to a reduction in fossil fuel consumption and a fall in the price of other fuels. Geothermal energy is used in the food industry for drying, evaporating, washing and maintaining hygiene, pasteurization of milk, processing of meat and fish, sterilization of equipment. Drying of fruits, vegetables and fish is one of the most widely used areas of application of geothermal energy in the food industry. It is used for lighting, cooling and powering pumps, compressors, conveyors, fans, machine for cutting meat, for processing, packaging and processing of water. The subject of the research is the representation of geothermal energy and the assessment of its energy and economic efficiency in the agribusiness of AP Vojvodina. The aim of the research is to determine the energy potential, ie the level and the possibility of using geothermal energy in Vojvodina agribusiness, as well as to present economic and environmental effects. The research uses a combination of quantitative-qualitative methods, induction and deduction, analysis and synthesis, abstraction and generalization, descriptor method, statistical method, comparative analysis, and others. The method of observation with participation will be applied. The case study method and the desk-research method will also be used. The results of the survey show that the Republic of Serbia has a high potential of geothermal resources (over 100 MW/m2), although it is much higher if the production of food, electricity, etc. is observed. The Republic of Serbia has 360 springs of thermal and thermal mineral waters, of which only 10% is used. In the territory of the Republic of Serbia there are important sources of geothermal water (more than 80 geothermal sources and wells with total thermal power of about 120 MW). The total reserves that the Republic of Serbia has at their disposal are significant, but geothermal energy reserves have not been sufficiently utilized. They amount to about 220 MW of thermal power, and the installed capacity of all capacities, which exploit 11 geothermal energy, is about 90 MW and are used to the greatest extent for balneological and recreational needs. AP Vojvodina is abundant with great wealth of geothermal resources. In the period 1969-1996. 72 wells were made in the AP Vojvodina, and in the period from 1997 to 2008, 6 drilled boreholes were drilled. The total heat output of hydrothermal wells is according to the data of "NIS Naftagas" from 2005 for 54 hydrothermal wells - 72,579 kW. The causes of minimal use are not in the technical solutions and technology of use, but in the lack of financial resources, knowledge and projects. Insufficient integration of scientific and production organizations, lack of heat pumps, relatively higher initial investments, lack of stimulative measures of financial support and tax policy negatively affects the use of geothermal energy. Putting into operation of existing wells requires a concrete techno-economic program of all installations, reconstructions and repairs, conversation with contractual users and finding new users and investors. The use of geothermal water in the production of Tilapia and African Soma has experimentally confirmed that it is possible to successfully cultivate these fish species in our conditions. The results so far show that direct water heating in ponds, using different energy sources, due to high prices is not economically viable, and the use of geothermal energy is imposed as an economical solution. Geothermal energy can be very useful in organic agriculture, since one of the principles is the use of renewable energy sources. In agribusiness in the area of AP Vojvodina, the use of geothermal energy is almost not represented. The potential of geothermal sources has not been fully exploited, either from the aspect of tourist demand. The available thermomineral waters in the AP Vojvodina provide more opportunities for the development of existing spas and construction of new spa facilities. Geothermal energy is a great potential for long-term, safe development of sustainable agricultural production and food industry, as well as other activities. Also, geothermal energy is a unique response to climate change, unstable and rising prices for conventional fuels, which increase the process of business. The cost of using geothermal installations is significantly lower 12 than the price of the conventional energy system. Economic analysis, which adheres to the latest guidelines for environmental requirements, the necessity of drilling and equipping the well, shows that wells above 40 oC and a strong spillage of about 60 m3/h are profitable, provided the consumer is able to use the entire potential of the well over 6000 ha/y. Prices of geothermal energy are lower than many other energy sources. High initial costs, exploration drilling risk, uneven subsidy policies, and demand indicate that geothermal energy is estimated as the cheapest source of energy in 2019. Studies on comparative costs of different energy sources show that geothermal energy is an affordable source of energy and that price is more favorable compared to other technologies (other than small hydro power plants) that are currently available. In the area of Kupinovo settlement from 1982-1985. extensive surveys were carried out, in order to examine the justification of investments in the exploitation of geothermal sources in agribusiness, balneology and for sports and recreational purposes. The most perspective area for obtaining thermal water according to the estimate, is a move east of Kupinova, towards the village of Progar, along the left bank of the Sava River. In the Kupinova area two hydrothermal wells, Kup-1/H and Kup-2/H were made. NIS-Naftagas from Novi Sad carried out the financing of drilling and project research. Bores showed excellent results. Village representatives suggested that the geothermal enrichment be used for the needs of an existing warm bathroom. The lack of financial resources has affected the realization of the project. The well is conserved, but can be quickly deconcentrated and the intentions of exploitation in the agribusiness are brought about. Bearing in mind that these drilled wells can be preserved, they could be equipped with small investments for the exploitation and heating of greenhouses, which would be built in close proximity. This is the most economical solution, provided the distance between the greenhouse is up to 2 km. A favorable location for the exploitation of geothermal water is located north of Staro Bečej (Medenjača and Veliki Rit) and northwest of Novi Bečej (Ljutovo - Veliki Rit). These would be optimal locations for drilling new wells, bearing in mind the requirements for efficient and economical greenhouse production. 13 Geothermal water in Kupinov can be used as a drink in accordance with its characteristics, while the water in Becej is a different case. This water has increased amounts of dissolved mineral matter (4 g/l), dissolved and free gases (mainly methane) and is medium aggressive against metals. It has greater demands in the technological process and its disposal after the exploitation, and its use could be for energy purposes. If in the assessment of the possibility of the geothermal deposit in Bečej, it starts with the parameters obtained on the well Bč-2/H, we can conclude that with such a borehole it can be heated 2-4 ha under the greenhouse. A complex analysis of thermomineral water of the well in Inđija - Inđ-3/H was performed. In accordance with the opinion of the Faculty of Medicine, the water contains several parameters in unauthorized quantities, so it can not be used as a drinking water. According to physical and chemical characteristics, thermo-mineral water can be used as an additive treatment in the field of medical rehabilitation, exclusively bathing. Geothermal potential in the AP Vojvodina has been insufficiently used, and the Vojvodina government has decided to support geothermal projects. Since we have significant sources of geothermal energy, we have the potential to improve its agriculture, aquaculture, environment, food industry, agroecotourism, balneology and other production and service activities through its increased use. Especially greenhouse and greenhouse production will be stimulated. The utilization of available geothermal energy in AP Vojvodina agribusiness is insufficient, although it has been proven that geothermal energy is more economical than other sources of energy. It is necessary for the state to stimulate scientific research in the field of thermal pump production, to provide greater subsidies for the use of renewable energy sources, to encourage the use of existing wells, which are neglected, as well as the drilling of new ones. The Republic of Serbia is dependent on energy imports, and urgently urges the development of a strategy, which will emphasize the importance of greater use of geothermal and other energy sources

Povezivanje dva ili više različitih sastojaka u jednu supstancu daje gotovo beskrajne mogućnosti za stvaranje novih inženjerskih materijala. Ovi materijali, koji se zovu kompozitni materijali, mogu se karakterizovati nizom različitih osobina, stoga ova čuda inženjerstva se široko koriste u skoro svim oblastima industrije i nauke, posebno u automobilskoj, električnoj i elektronskoj, vazduhoplovnoj, građevinskoj i mašinskoj industriji, sportu i razonodi itd. Primena kompozitnih materijala je svestrana i u svim sferama industrije i života, te se elektroprovodni kompoziti koriste u industriji računara i elektronskih komponenti, elektroopremi, avioindustriji, kao hladni varovi. Ovi materijali se koriste i kao prekidači, elektromagnetni štitovi, kao zaštita od strujnog i naponskog udara, provodni lepkovi, u građevinarstvu., kao elektrode za solarne ćelije na bazi boja. Oni su takođe našli tehnološku primenu kao grejači sa samoregulatorima, elektronski i hemijski nosevi i senzori, fototermički optički snimači, kao adsorbensi i hemijski i elektrohemijski katalizatori, i u novije vreme u uređajima za skladištenje i konverziju električne energije. Elektroprovodni polimerni kompoziti imaju nekoliko prednosti u odnosu na svoje polazne gradivne supstance, a te prednosti uklјučuju manje troškove i lakoću proizvodnje, manju težinu, visoku fleksibilnost, veću apsorpcionu moć kada su u pitanju mehanički udari i mehanička naprezanja, imaju povećanu otpornost prema koroziji i izrazitu kontrolu provodnosti. U ovoj doktrorskoj disertaciji su prikazani eksperimentalni rezultati istraživanja svojstava kompozitnih materijala na bazi poli(metil metakrilatne) - PMMA, poli(laktidne)-PLA i poli(hidroksi butiratne)-PHB matrice punjenih elektrolitičkim bakarnim prahom. Udeо metalnog punioca, odnosno elektrolitički dobijenog bakarnog praha u ispitivanim kompozitnim uzorcima variran je u opsegu od 0.5-8.8 vol. %, a uzorci su pripremljeni u molderu na povišenim temperaturama. U eksperimentalnom delu za analizu i karakterizaciju metalnog punioca i polimernih matrica, te pripremljenih kompozita korišćene su različite eksperimentalne metode i tehnike. Ove tehnike su uključivale skening elektronsku mikroskopiju (SEM) i mikroskopiju atomskih sila (AFM), čijom primenom su urađene mikrostrukturne i morfološke analize, a određena je veličina i raspodela čestica konstituenata, kao i i električna provodnost kompozita u zavisnosti od udela punioca metodom impedansne spektroskopije (IS)... Connecting two or more different ingredients into one substance gives almost endless possibilities for creating new engineering materials. These materials, which are called composite materials, can be characterized by a variety of different properties, and, therefore these engineering wonders are widely used in almost all areas of industry and science. In particular, these materials are widely used in automotive industry, electrical and electronic industry, aerospace, civil construction and mechanical engineering, sports and leisure, etc. Composites with metal fillers have found their use as electromagnetic protection of computers and electronic equipment, conductive adhesives for electronic equipment, cold welds, switches, devices for removal of static electricity, voltage protection devices, in dye based solar cells. They also found technological applications in self-regulating heaters, as photothermic optical recorders, chemical sensors and electronic noses, chemical and electrochemical catalysts and adsorbents, supercapacitors. The electroconductive polymer composites have several advantages over their constituents, and these advantages include lower costs and ease of production, high flexibility, lower weight-to-price ratio, greater ability to absorb mechanical impacts, corrosion resistance and conductivity control. The experimental results of the properties’ investigations of composite materials based on poly (methyl methacrylate) - PMMA, poly (lactide) - PLA and poly (hydroxybutyrate) - PHB matrices filled with electrolytic copper powder are shown in this thesisr. The volume fraction of metal filler in investigated composite materials was varied in the range of 0.5-8.8 vol. %, and the samples were prepared in laboratory molder at elevated temperatures. Various experimental methods and techniques were used in the experimental part for the analysis and characterization methods and tecniques were performed on the starting constituents and investigated composites. Microstructural and morphological analysis was performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The size and particle vii distribution of the constituent was investigated, as well as the electrical conductivity of the composites in dependance on volume fraction of filler. The thesis deals with the synthesis and characterization of electroconductive composite materials, primarily based on biodegradable polymers. Polymers were mixed with electrochemically, i.e. galvanostatically produced copper powder. The effects of particle size and morphology on the conductivity and percolation threshold of the obtained composites was studied. Characterization included different testing techniques: SEM, AFM, TGA, DSC, FTIR, particle size distribution and conductivity measurement by the impedance spectroscopy method...

Composite materials nowdays are increasing industrial applications worldwide. Composites based on polymers with conductive fillers are getting wider research focus primarily because of their growing importance from the point of application in: electronics, medicine, industry and so on. Besides mentioned above, these composites have found application as contact conductive materials, electromagnetic and radio wave shields, photothermal optical recorders, electronic noses sensitive to certain chemicals, as well as economically acceptable catalysts. The results of experimental studies of the properties of composite materials based on lignocellulosic (LC) and Poly(methyl methacrylate) (PMMA) matrices filled with electrolytic copper are presented in this chapter. Volume fractions of metal fillers in tested composite materials were varied in the range of 1.6–30% (v/v), and the samples were prepared both by compression – cold pressing and hot moulding. The results have shown that shape and morphology of the copper powder, and filler at all, play a significant role in the phenomenon of electrical conductivity of the prepared samples, as well as on the appearance of percolation threshold. The particles with highly developed free surface areas like dendrites, having highly branched structures (such as electrolitically obtained copper powder particles) can much easier form interparticle contacts at lower filler volume fractions than the particles with more regular surface. Layered electrical conductivity throughout the entire sample volume was observed, whereby the resistance of the inner layers was the leading processes of the entire composite resistance. It can be seen that the resistance has increased due to increased contribution of the polymer matrix inner surface area as the frequency decreased. Conductivity measurements have shown typical S-shaped dependence with the percolation transition from nonconductive to conductive region. For all the processing pressures, the percolation threshold for smaller particle sizes was lower than for larger ones. This difference has increased with the increase of processing pressure. A significant increase in the electrical conductivity have been observed when the content of conductive filler in the composites reached the percolation threshold. The effect of particle packaging and pronounced interparticle contact with smaller, highly porous and dendritic particles with large specific surface areas, led to a “shift” of percolation threshold to lower values of filler volume fractions. It was noticed that this transition occurred at lower values of filler content than it was stated in the literature, which is due to the use of fillers with large specific surface areas.

The results of experimental studies of the properties of composite materials based on Poly (lactic acid) (PLA) and Poly (3-hydroxybutyrate) (PHB) matrices filled with electrolytic copper powder, having very high dendritic structure, are presented in this manuscript. Copper powder volume fractions used as filler in all prepared composites were varied in the range of 0.5-6.0 %(v/v). The samples were prepared by hot molding injection at 170°C. Influence of particle size and morphology, as well as influence of matrix type on the conductivity and percolation threshold of the composites were examined and characterization included: Electrical conductivity measurements using Impedance Spectroscopy (IS), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier-transform Infrared Spectroscopy (FTIR). Presence of three dimensional conductive pathways was confirmed. The obtained percolation threshold of 2.83 %(v/v) for PLA and 3.13 %(v/v) for PHB composites was measured, which is about three times lower than the one stated in the literature for similar composites. This property is ascribed to different morphology of filler used in investigation.