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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Karakterizacija proizvodnih parametara alata za utiskivanje izrađenih tehnikom 3D štampe / Characterisation of manufacturing parameters of embossing dies produced by 3D printing technique

Banjanin Bojan 09 November 2018 (has links)
<p>U disertaciji su predstavljena istraživanja uticajnih parametara u procesu izrade alata za utiskivanje tehnikom aditivne proizvodnje, tačnije tehnikom deponovanja istopljenog materijala (FDM). Izrađena je kontrolna grupa alata za utiskivanje konvencionalnom tehnikom hemijskog nagrizanja i SLA tehnikom 3D štampe. Cilj istraživanja je definisanje optimalnih procesnih parametara izrade alata za<br />utiskivanje FDM tehnikom štampe. Ustanovljena je metodologija za karakterizaciju proizvodnih parametara koja se može primeniti na ostale tehnike aditivne proizvodnje. Analizom dobijenih rezultata i zaključaka istraživanja ustanovljena su ograničenja i mogućnosti zamene konvencionalnih alata za utiskivanje alatima izrađenim tehnikama 3D štampe.</p> / <p>The study of the influencing parameters in the production process of embossing dies using Fused Deposition Modelling (FDM) additive manufacturing technique, was investigated in this dissertation. Embossing dies, produced using conventional chemical etching and vat photopolymerization technique, were developed as a control group. This research aims to define the optimal process parameters of Fused Deposition Modelling (FDM) in embossing dies manufacturing. A new methodology for the characterisation of production parameters, which can be applied to other additive production techniques, has been established. By analysing the results and the conclusions of this research, the possibility of replacing<br />conventional embossing dies produced using 3D printing techniques has been established as well as its limitations.</p>
2

Техничко-стилске карактеристике драматургије Леонида Андрејева у периоду од 1905. до 1910. године / Tehničko-stilske karakteristike dramaturgije Leonida Andrejeva u periodu od 1905. do 1910. godine / Stylistic and Technical Characteristics of Leonid Andreyev’s Plays (1905-1910)

Panaotović Melina 15 June 2019 (has links)
<p>Menjajući poetike, istražujući u oblasti forme, Leonid Andrejev u svom ranom dramskom stvarala&scaron;tvu ostaje veran svojoj inicijalnoj ideji: on promi&scaron;lja ljudsku misao, njenu prirodu i njene moguće manifestacije, kao i moć i nemoć ljudske misli u svetu koji ga okružuje. U prvom periodu svog ranog stvarala&scaron;tva, definisanom kao realistički teatar, pisac sagledava tri različite manifestacije ljudske misli: nauku, religiju i revoluciju. U perodu potrage za novom dramskom formom, supstancionalnom teatru, misao dolazi u sukob sa supstancom i rađa se ideja da ljudska misao nije svemoguća, to jest da čovek ne može da živi vođen isključivo razumnim načelom. U trećem periodu svog ranog dramskog stvarala&scaron;tva, takozvanom melodramskom teatru, pisac se naizgled udaljava od svoje osnovne teme i afirmi&scaron;ući studentske uspomene, na biografskoj građi stvara dve psiholo&scaron;ke melodrame.<br />&nbsp; U sva tri navedena teatra, realističkom, supstancionalnom i melodramskom, pisac se služio bogatim aresenalom tehničko-stilskih sredstava. U radu se tumači upotreba hromatskog i muzičkog prosedea, priroda i funkcija didaskalija, portetna metaforičnost likova, kao i simbolični plan drama, te njihove tematske i idejne koncepcije.<br />&nbsp;&nbsp; Zaključak je da je u potrazi za formom, u tim spontanim smenama poetika i bogatom kori&scaron;ćenju tehničko-stilskih sredstava (npr., montažnost dramskog teksta, kolektivni monolog, personalizacija i depersonalizacija aktera radnje; upotreba metafore, poređenja, metonimije, sinegdohe, sinestezije, groteske, lirskih paralelizama itd.), L. Andrejev ostao dosledan svojoj primarnoj ideji, promi&scaron;ljanju o moći i nemoći ljudske misli. Ta ista ideja u&scaron;la je u osnovu teatra panpsihe, koji je okarakterisao naredni plodan period ovog dramskog pisca.</p> / <p>Although he was not consistent in his approach when poetics and the form were concerned, Leonid Andreyev never gave up on the initial idea in his early plays: in them he was deeply involved in consideration of human thought, its nature and its possible manifestations, as well as its power, or the lack of it. In the first phase of his early works, which is in this thesis termed a realist theater, the playwright takes into consideration three different manifestations of human thought: science, religion and revolution. During the period in which he was searching for a new form for his plays, the so-called substantialist theater, thought is confronted with substance, upon which a new idea emerges, that of powerlessness of human thought&ndash; human beings cannot live their lives based solely on the principle of rationality. In the third period of his early writing, the so-called melodramatic theater, the author seemingly deviates from main theme, and by returning to his university days, creates two autobiographical, psychological plays.<br />&nbsp;&nbsp; In all three theaters, the realist, the substantialist and the melodramatic, the author uses a rich palette of technical and stylistic devices. This thesis offers analyses of chromatic and musical principles; the nature and function of stage directions; metaphorical nature of the characters; as well as the symbolism present in the plays.<br />&nbsp;&nbsp; Searching for the form, through spontaneous shifts between different poetics and an array of technical and stylistic devices (such as editing of plays, collective monologue, personalization and depersonalization of the characters, the use of metaphor, simile, metonymy, synecdoche, synesthesia, grotesque, lyrical parallelisms), Leonid Andreyev remained loyal to his initial idea of pondering the power and weakness of human thought. This idea has become a constitutive part of pan-psyche theater that marked the next, rather fruitful period of this playwright.</p>
3

Funkcionalni materijali na bazi elektrospinovanih nanovlakana / Functional materials based on electrospun nanofibers

Miletić Aleksandra 01 November 2019 (has links)
<p>Funkcionalni materijali na osnovu elektrospinovanih nanovlakana nalaze sve veću primenu u raznim oblastima industrije: biomedicina, farmacija, senzori, filrtacija, ambalaža itd. Elektrospining tehnika je jedna od metoda za dobijanje materijala na osnovu nanovlakana iz polimernih rastvora kori&scaron;ćenjem visokog napona. Kori&scaron;ćenje elekrospining tehnike ima brojne prednosti u odnosu na konvencionalne tehnike, pre svega zbog lakoće inkorporacije aktivne komponente u polimernu matricu, a i specifične morfologije i 3D strukture, jer usled nanometarskih dimenzija, vlakna imaju veliki odnos specifične povr&scaron;ine i zapremine i poroznosti, samim tim veliku kontaktnu povr&scaron;inu sa supstratima, reaktivnim agensima i mikroorganizmima. Zbog proizvodnje materijala na nanonivou, aktivna komponenta se fino dispergije u polimernoj matrici i time se obezbeđuje bolja aktivnost ovih materijala. Za razliku od konvencionalnih filmova, funkcionalni materijali na osnovu elektrospinovanih nanovlakana su aktivni po celoj zapremini. Cilj ove doktorske disertacije bio je optimizicija procesnih parametara elektrospininga i validacija aktivnosti funkcionalnih materijala za različite primene, &scaron;to je postignuto pravilnim odabirom materijala i aktivnih komponenti, optimizacijom sastava materijala, karakterizacijom materijala adekvatnim metodama i validacijom aktivnosti materijala. Razvijeni su materijali za primenu u oblasti kozmetike, ambalaže, filtracije, senzora, stomatologije i provodnih materijala, čija je aktivnost verifikovana u laboratorijskim uslovima (TRL 4).</p> / <p>Functional materials based on electrospun nanofibers are increasingly used in various fields of industry: biomedicine, pharmacy, sensors, filtration, packaging, etc. Electrospining technique is one of the methods for obtaining nanofibers from polymer solutions using high voltage. The use of electrospinning technique has many advantages over conventional techniques, primarily because of the ease of incorporation of the active component into the polymer matrix, as well as the specific morphology and 3D structure, because due to the nanometer dimensions, the fibers have a large ratio of specific surface area to volume and porosity, and thus a high contact surface with substrates, reactive agents, and microorganisms. Due to the production of materials at the nanoscale, the active component is finely dispersed within the polymer matrix, thereby ensuring better activity of these materials. Unlike conventional films, functional materials based on electrospinned nanofibers are active throughout the volume. The aim of this PhD thesis was to optimize the electrospining process parameters and validate the activity of functional materials for various applications, which was achieved by proper selection of materials and active components, optimization of material composition, characterization of materials by appropriate methods and validation of material activity. Materials have been developed for use in the fields of cosmetics, packaging, filtration, sensors, dentistry and conductive materials, the activity of which has been verified under laboratory conditions (TRL 4).</p>
4

Karakteristike glasa i metodički pristupi razvoju glasa u funkciji profesionalnih aktivnosti / Voice Characteristics and MethodicalApproaches in the Voice Development for thePurpose of Professional Activities

Vitkai Kučera Agota 04 March 2013 (has links)
<p>Predmet doktorske disertacije je utvrđivanje stanja glasa budućih eltinih vokalnih profesionalaca (studenata glume), upoređivanje sa stanjem glasa studenata nevokalnih<br />zanimanja, utvrđivanje metodičkih postupaka za razvoj glasa, kao i utvrđivanje uticaja glasovnih vežbi primenom &quot;WIC&quot; tehnike na stanje glasa kod ispitanika kojima je potvrđen vokalni poremećaj.</p> / <p>This PhD thesis aims to establish the state of voice in future elite vocal professionals (drama students), to compare it with the state of voice in students of non-vocal professions, to determine the methodic procedures for the voice development, as well as to ascertain the effects of vocal exercises by application of &ldquo;WIC&rdquo; technique on the state of voice in respondents who were found to suffer from the vocal disorder.</p>
5

Modeliranje energetskih karakteristika dvostrukih ventilisanih fasada / MODELLING OF THE ENERGY CHARACTERISTICS OF A NATURALLY VENTILATED DOUBLE SKIN FACADE

Andjelković Aleksandar 23 April 2015 (has links)
<p>Predmet istraživanja načelno se odnosi na razmatranje koncepta dvostrukih ventilisanih fasada (DVF) i njihov uticaj na energetsku efikasnost objekta. Ovaj koncept predstavlja jedan od primera adaptivnih fasada. Plan istraživanja zasnovan je na eksperimentalnom radu (na realnom objektu) i na numeričkim simulacijama modela objekta. Rezultati eksperimentalnog dela istraživanja pokazuju na koji način zavise termičke osobine objekta sa DVF od trenutnih meteorolo&scaron;kih uslova. Takođe, ovi rezultati poslužili su za fino pode&scaron;avanje modela i za postizanje &scaron;to vernije slike realnog objekta. Kriterijum prihvatljivosti, kada je model potvrđen, definisani su sa preporučenim statističkim indikatorima. Na taj način, formiran model u daljoj analizi je kori&scaron;ćen za definisanje sezonskih operativnih strategija. Rezultati simulacija za sve predložene operativne strategije, ocenjuju kakav je njihov uticaj na potro&scaron;nju energije za grejanje i klimatizaciju posmatranog objekta. Poređenjem sa modelima objekta sa tradicionalnom fasadom, pokazana je opravdanost primene koncepta DVF u klimatskim uslovima Beograda.</p> / <p>Research generally refers to the consideration of the concept of a double skin facades (DSF) and their impact on energy efficiency of the building. This concept is an example of adaptive facades. The research plan is based on experimental work and on the numerical model simulation. The results of experimental research works show how energy characteristics of the object with the DSF depend of current meteorological conditions. Also, these results were used to fine-tune the model to achieve as closely as possible the real presentation of the real building. The criterion of eligibility, when the model is verified, are defined with the recommended statistical indicators. Validated model in further analysis is used to define seasonal operational strategies. The simulation results for all proposed operational strategies, assess what is their impact on the building energy consumption for heating and air-conditioning. Compared to the models with a traditional facade, analysis show justification for the application of the concept of DSF in the climatic conditions of Belgrade.</p>
6

Procena rezultata lečenja unutarzglobnih višekomadnih preloma gornjeg i donjeg okrajka potkolenice aparatom po Ilizarovu / Assessment of treatment results of intraarticulary multifragmentary fractures of upper and lower part of the lower leg by Ilizarov apparatus

Lalić Ivica 24 June 2016 (has links)
<p>Kompleksnost visokoenergetskih preloma platoa i pilona tibije i njihova udruženost sa značajnim povredama mekog tkiva oko pripadajućeg zgloba veoma je dobro opisana. Lečenje ima za cilj da multifragmentarni prelomi platoa i pilona tibije postanu stabilni, artikularno poravnani, bezbolni, da koleno i skočni zglob budu pokretni i da se minimizira rizik do nastanka posttraumatskog osteoartritisa. Aparat po Ilizarovu sa nategnutim iglama, koristi opterećenje da stvori jedinstvenu podr&scaron;ku za zglob i stabilnu imobilizacju preloma da se postigne njegovo srastanje. Ovo omogućuje ranu pokretljivost zgloba bez rizika od gubitka redukcije. Cilj istraživanja je procena i poređenje rezultata lečenja unutarzglobnih vi&scaron;ekomadnih preloma kostiju proksimalnog i distalnog okrajka potkolenice tretiranih spoljnjim unilateralnim rigidnim fiksatorom i aparatom po Ilizarovu primenom ASAMI ko&scaron;tanog skoring sistema i funkcionalnog skoring sistema po Karlstrom &ndash; Olerudu.Takođe je jedan od ciljeva istraživanja bio da se uoče faktori koji utiču na različite rezultate lečenja unutarzglobnih vi&scaron;ekomadnih preloma kostiju gornjeg i donjeg okrajka potkolenice tretiranih spoljnim unilateralnim rigidnim fiksatorom i aparatom po Ilizarovu. Istraživanje je dizajnirano kao kontrolisana komparativna klinička studija a podaci su se prikupljali retrospektivno i delom prospektivno na osnovu medicinske dokumentacije od 2008. do 2013. godine. Studija je u potpunosti izvedena na Klinici za ortopediju i traumatologiju Kliničkog centra Vojvodina u Novom Sadu. Studija je obuhvatila ukupno 103 ispitanika kod kojih je u toku 2008 do 2013. godine postavljena dijagnoza unutarzglobnog vi&scaron;ekomadnog preloma gornjeg ili donjeg okrajka tibije. Ispitanici koji su obuhvaćeni ovim kliničkim istraživanjem razvrstani su u tri grupe: Prvu grupu od 53 ispitanika činili su oni sa vi&scaron;ekomadnim unutarzglobnim otvorenim ili zatvorenim prelomima gornjeg ili donjeg okrajka kostiju potkolenice lečenih isključivo spoljnjim unilateralnim rigidnim fiksatorom. Drugu grupu ispitanika, njih 31, činili su oni sa vi&scaron;ekomadnim unutarzglobnim otvorenim ili zatvorenim prelomima gornjeg ili donjeg okrajka kostiju potkolenice lečenih isključivo aparatom po Ilizarovu. Treću grupu činila su 19 ispitanika sa vi&scaron;ekomadnim unutarzglobnim otvorenim ili zatvorenim prelomima gornjeg ili donjeg okrajka kostiju potkolenice koji su lečenje započeli spoljnjim unilateralnim rigidnim fiksatorom, a u kasnijem periodu zbog nastalih komplikacija (lo&scaron;e srastanje, produženo srastanje, nesrastanje, infekcija, pseudoartroza) lečenje nastavili konverzijom spoljnjeg unilateralnog rigidnog fiksatora u aparat po Ilizarovu. Osnovni izvor podataka za prikazano istraživanje bio je protokol formiran za svakog bolesnika pojedinačno, istorije bolesti i poliklinička evidencija. Za potrebe istraživanja dizajniran je protokol istraživanja gde su se prikupljeni podaci analizirali hronolo&scaron;ki : podaci o pacijentu, klinički nalaz na prijemu, postoperativni tok, monitoring aparata, klinički nalaz na otpustu i klinički nalaz na kontrolama od 6, 12 i 18 meseci. Kliničke nalaze na kontrolama na 6, 12 i 18 meseci beležili smo upotrebom skoring sistema ASAMI ( Udruženja za istraživanje i primenu metoda po Ilizarovu) &ndash; za ko&scaron;tane rezultate, i Karlstrom &ndash; Oleruda za procenu funkcionalnih rezultata. Neki do najvažnih rezultata dobijenih prilikom ovog istraživanja jesu da je najbrže vreme srastanja imala grupa Ilizarov, nakon 16&plusmn;2 nedelja. Grupa konverzija zabeležila je prosečno vreme srastanja u 17&plusmn;2 nedelji, dok je kod ispitanika u grupi fiksator zabeženo srastanje u 21&plusmn;4 nedelji. Pojava povr&scaron;nih i dubokih infekcija značajno je veća kod grupe tretiranih spoljnim unilateralnim fiksatorom nego kod grupa tretiranih aparatom po Ilizarovu. Vreme postizanje ranog, punog oslonca na operisani ekstremitet je značajno kraće kod grupe Ilizarov i konverzija nego kod grupe fiksator. Procena ko&scaron;tanih rezultata kori&scaron;ćenjem ASAMI bodovnog sistema ko&scaron;tanog srastanja ukazuje na statistički značajno bolje rezultate kod grupa Ilizarov i konverzija u odnosu na grupu spoljnji fiksator u periodu praćenja i analize na 6,12 i 18 meseci. Funkcionalni rezultati primenom sistema funkcionalne evaluacije po Karlstrom &ndash; Olerudu govore u prilog značajno statistički boljim rezultatima kod grupe Ilizarov i konverzija u odnosu na grupu spoljni fiksator u periodima praćenja i analize na 6,12 i 18 meseci. Na osnovu dobijenih rezultata dolazimo do zaključka da je tretman ispitanika sa multifragmentarnim, intraarikularnim prelomima gornjeg i donjeg okrajka kostiju potkolenice znatno efikasniji aparatom po Ilizarovu &scaron;to sveukupno daje smernice za brži i kvalitetniji oporavak ispitanika i njihov povratak svakodnevnim aktivnostima sa &scaron;to manjim posttraumatskim sekvelama.</p> / <p>The complexity of high-energy fractures of the tibia plateau and pilons and their association with significant violations of the soft tissue around the corresponding joint is well described in the literature. Main aim of the treatment is to multiple fractures of the tibia plateau and pilon become stable, articularly aligned, without pain, and with full motion in the knee and ankle joint with minimum risk for post-traumatic osteoarthritis. Ilizarov apparatus with taut needles is used to create a unique load support for the ankle and create conditions for good healing. This strong stability allows early joint movement, without risk of loss position of fracture parts. The aim of this research is assessment and comparation of the results of treatment, for intraarticular multiple fractures of the proximal and distal part of lower leg tretaed with unilateral external rigid fixator and Ilizarov apparatus, with ASAMI bone scoring system and functional scoring sistem by Karlstrom &ndash; Olerud. One of the goals of the study was to detect factors which affecting different treatment results of the intraarticular multiple fractures of the proximal and distal part of lower leg, tretaed with unilateral external rigid fixator and Ilizarov apparatus. The study was designed as a controlled comparative clinical study and data were collected retrospectively and prospectively form medical records from 2008 to 2013. The study has been fully implemented at the Department for orthopedic surgery and traumatology in the Clinical Center of Vojvodina in Novi Sad and included 103 patients who had intraarticular multiple fractures of the proximal and distal part of tibia. Subjects covered in this clinical study were classified into three groups: The first group of 53 patients were with intraartiulary multifragmentary open or closed fractures of the upper or distal part of lower leg, treated exclusively with unilateral external rigid fixator. The second group included 31 patients with intraarticular open or closed fractures of the upper or distal lower leg, treated exclusively with Ilizarov apparatus. 19 patients made the third group with intraarticulary open or closed fractures of the upper or distal lower leg, which were treated at the begining with unilateral external rigid fixator and later because of the complications (poor or prolonged healing, nonunion, infection and pseudoarthrosis) tretment was continued by Ilizarov apparatus. The main source of data for this study was protocol wich was established for each patient individually. In this protocol collected data analyzed by date: patient data, clinical findings at admission, postoperative course, monitoring apparatus, clinical findings at discharge and clinical findings at the controls which were at 6, 12 and 18 months after surgery. Clinical findings at control examinations (6, 12 and 18 months after surgery), we recorded by scoring system ASAMI (Association for the Study and Application of the Methods of Ilizarov) - that represent the results of the bone healing, and Karlstrom - Olerud for assessment functional outcomes. The most important results were: the fastest time of bone union was in the group of Ilizarov, and it was after 16 &plusmn; 2 weeks and the third group (conversion group) recorded an average time after 17 &plusmn; 2 weeks, while the patients in the first group (external fixator) had average time of union after 21 &plusmn; 4 week. The appearance of superficial and deep infection was significantly higher in the group treated with unilateral external fixator than in the group treated by the Ilizarov apparatus. Fastest full weight bearing on the injured leg, had patients in the group treated with Ilizarov apparatus. Evaluation of results using bone ASAMI fusion scoring system indicating a statistically significantly better results in the conversion and Ilizarov group compared to the group of external fixator in the period of monitoring at 6,12 and 18 months after surgery. Functional results by Karlstrom - Olerud scoring system show statistically significantly better results in the Ilizarov and conversion group contrary to the external fixator group in periods of monitoring at 6,12 and 18 months. Based on these results we conclude that the treatment of subjects with intraarticulary, multifragmentary fractures of the upper and lower part of the lower leg are more efficient after Ilizarov apparatus which provides overall guidance for faster and better recovery of patients and their return to their daily activities with minimal post-traumatic sequelae.</p>
7

Savremene metode ekstrakcije očajnice (Marrubium vulgare L.) i sušenje odabranih ekstrakata, hemijski sastav i biološke aktivnosti / Contemporary methods of extraction of white horehound (Marrubium vulgare L.) and drying of selected extracts, chemical composition and biological activities

Gavarić Aleksandra 11 December 2020 (has links)
<p>U okviru ove disertacije ispitane su mogućnosti primene savremenih metoda za dobijanje tečnih ekstrakata (ultrazvučna ekstrakcija, mikrotalasna ekstrakcija i ekstrakcija subkritičnom vodom) i lipofilnih ekstrakata (ekstrakcija superkritičnim ugljendioksidom) bogatih polifenolima iz nadzemnog dela očajnice (Marrubium vulgare L.). Tečni ekstrakti su optimizovani primenom eksperimentalnog dizajna i metode odzivne povr&scaron;ine, i podvrgnuti su spray drying tehnici su&scaron;enja. Tečni i suvi ekstrakti su detaljno ispitani po pitanju hemijskog sastava i biolo&scaron;ke aktivnosti, antimikrobne i in vitro antihiperglikemijske aktivnosti.<br />Za svaku od navedenih ekstrakcionih tehnika ispitan je uticaj glavnih parametara: ultrazvučna ekstrakcija (temperatura, vreme ekstrakcije i snaga ultrazvuka), mikrotalasna ekstrakcija (koncentracija etanola, vreme ekstrakcije i snaga mikrotalasa) i ekstrakcija subkritičnom vodom (temperatura, vreme ekstrakcije i koncentracija HCl u ekstragensu). Kod tečnih ekstrakata dobijenih ultrazvučnom i mikrotalasnom ekstrakcijom na optimizovanim uslovima utvrđeno je prisustvo hlorogenske kiseline i kvercetina koji nisu detektovani u maceratima. Ispitana je antimikrobna aktivnost oba ekstrakta i utvrđeno da je B. cereus najosetljiviji bakterijski soj, dok je u slučaju kvasaca S. cerevisiae posebno osetljiv na oba ekstrakta. Pored ove aktivnosti ispitana je i in vitro antihiperglikemijska aktivnost oba ekstrakta prema &alpha;-amilazi i &alpha;-glukozidazi, pri čemu ultrazvučni ekstrakt pokazuje veću antihiperglikemijsku aktivnost (50,63% inhibira &alpha;-amilazu i 48,67% inhibira &alpha;-glukozidazu) &scaron;to se potencijalno može objasniti prisustvom hlorogenske kiseline (33,11 &mu;g/mL) i kvercetina (34,88 &mu;g/mL). U subkritičnom ekstraktu, dobijenom na optimalnim uslovima, detektovano je jedino prisustvo hidroksi metilfurfurala usled čega ovaj ekstrakt nije podvrgnut ispitivanju antimikrobne i antihiperglikemijske aktivnosti.<br />U cilju ekstrakcije lipofilnih komponenata M. vulgare primenjene su destilacija etarskog ulja (0,05%), Soxhlet ekstrakcija (3,23%) i ekstrakcija superkritičnim ugljendioksidom na pritiscima 100, 200 i 300 bar i temperaturama 40, 50 i 60 &deg;C. Najdominantnija komponenta u svim dobijenim superkritičnim ekstraktima je hemotaksonomski marker marubiin koji nije identifikovan u Soxhlet ekstraktu.<br />Tečni ekstrakti dobijeni ultrazvučnom i mikrotalasnom ekstrakcijom na optimizovanim uslovima i macerat su osu&scaron;eni spray drying tehnikom (uz dodatak 10 i 50% maltodekstrina) u cilju dobijanja stabilnije forme suvog ekstrakta. Suvim ekstraktima su određene najznačajnije fizičke osobine i hemijski sastav kao i antimikrobna i antihiperglikemijska aktivnost kako bi se procenila mogućnost njihove inkorporacije u funkcionalnu hranu, dijetetske suplemente ili u formulaciji različitih gotovih proizvoda koji se primenjuju preventivno ili radi pobolj&scaron;anja zdravlja ljudi.</p> / <p>Within the scope of this dissertation, the possibilities of applying modern methods for obtaining liquid (ultrasonic extraction, microwave extraction and subcritical water extraction) and lipophilic extracts (extraction with supercritical carbon dioxide) rich in polyphenols from the aboveground part of white horehound (Marrubium vulgare L.) were examined. Liquid extracts were optimized using an experimental design and response surface method, and subjected to spray drying. Liquid and dry extracts have been extensively examined for their chemical composition and biological activity, antimicrobial and in vitro antihyperglycaemic activities.<br />For each of these extraction techniques, the influence of the main parameters was examined: ultrasonic extraction (temperature, extraction time and ultrasound power), microwave extraction (ethanol concentration, extraction time and microwave power) and subcritical water extraction (temperature, extraction time and HCl concentration in the extractant). Liquid extracts obtained by ultrasonic and microwave extraction under optimized conditions revealed the presence of chlorogenic acid and quercetin, which were not detected in macerates. The antimicrobial activity of both extracts was examined and B. cereus was found to be the most sensitive bacterial strain, whereas in the case of yeast S. cerevisiae was particularly sensitive to both extracts. In addition to this activity, the in vitro antihyperglycaemic activities of both extracts against &alpha;-amylase and &alpha;-glucosidase were investigated, with ultrasound extract showing higher antihyperglycemic activity (50.63% inhibited &alpha;-amylase and 48.67% inhibited &alpha;-glucosidase) which could potentially be explained by the presence of chlorogenic acid (33.11 &mu;g/mL) and quercetin (34.88 &mu;g/mL). In the subcritical extract, obtained under optimal conditions, only the presence of hydroxy methylfurfural was detected, and this extract was not subjected to antimicrobial and antihyperglycemic activity.<br />For the extraction of lipophilic components of M. vulgare, distillation of essential oil (0.05%), Soxhlet extraction (3.23%) and extraction with supercritical carbon dioxide at pressures of 100, 200 and 300 bar and at temperatures of 40, 50 and 60 &deg; C were applied. The most dominant component in all the supercritical extracts obtained is the chemotaxonomic marker marubiin, which was not identified in the Soxhlet extract.<br />The liquid extracts obtained by the ultrasound and microwave extraction under optimized conditions and the macerate were spray dried (with the addition of 10 and 50% maltodextrin) to obtain a more stable form of the dry extract. Dry extracts underwent determination of the most important physical properties and chemical composition as well as antimicrobial and antihyperglycemic activities to evaluate their incorporation into functional foods, dietary supplements or in the formulation of various finished dosage forms that are administered preventively or to improve human health.</p>

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