<p>Aktuelni problem industrije proizvodnje hrane za ribe jeste smanjena dostupnost i visoka<br />cena ribljeg bra&scaron;na, tradicionalnog izvora proteina u hrani za ribe, koja je direktna posledica rasta sektora akvakulture i visoke potražnje za ovim kvalitetnim proteinskim hranivom. Delimična ili potpuna zamena ribljeg bra&scaron;na visokoproteinskim sirovinama biljnog porekla u recepturama za ishranu riba, uz iznalaženje novih alternativnih visokoproteinskih sirovina pristup je kojim se prevazilazi ovaj problem i koji ima potencijal da obezbedi održivost celokupne industrije hrane za ribe u budućnosti. U okviru ove disertacije predloženo je novo, relativno jednostavno i jeftino tehnolo&scaron;ko re&scaron;enje za suvo frakcionisanje suncokretove sačme, čijom bi se primenom dobile njene visokoproteinske frakcije kao potencijalne proteinske sirovine biljnog porekla za zamenu ribljeg bra&scaron;na u hrani za ribe. Shodno tome, istraživanja ove disertacije urađena su u dve odvojene faze, gde je prva, faza vazdu&scaron;ne klasifikacije, imala za cilj ispitivanje mogućnosti primene kombinacije postupaka usitnjavanja suncokretove sačme mlinom čekidarom i vazdu&scaron;ne klasifikacije ovako usitnjene sačme primenom vazdu&scaron;nog gravitacionog kaskadnog, cik-cak, klasifikatora u cilju dobijanja frakcija povedanog sadržaj proteina u odnosu na polaznu sačmu. Nezavisni parametri usitnjavanja i klasifikacije bili su prečnik otvora sita (POS) čekidara (3, 2 i 1 mm), protok<br />klasifikacionog vazduha (5, 8,7 i 12,5 m³/h) i jačina oscilacije vibro dozatora (JOVD)<br />klasifikatora (30, 60 i 90% maksimuma). Zavisne promenljive bile su sadržaj proteina u<br />dobijenim frakcijama i njihov prinos. Primenjen je 3x3x3 potpuni faktorijalni eksperimentalni dizajn prema metodi odzivne povr&scaron;ine. U cilju dobijanja frakcije sa &scaron;to<br />većim sadržajem proteina, u &scaron;to većem prinosu, kombinacija postupaka usitnjavanja i<br />vazdu&scaron;ne klasifikacije je optimizovana primenom regresione analize, analize glavnih<br />komponenata (PCA analiza), analize varijanse, kao i računske dinamike fluida (CFD analiza), kojom je dobijeni kompjuterski model vazdu&scaron;ne klasifikacije suncokretove sačme poređen sa eksperimentalno dobijenim rezultatima. Cik-cak vazdu&scaron;ni klasifikator uspe&scaron;no je primenjen za razdvajanje usitnjene suncokretove sačme na grubu i finu frakciju. Pri povećanju protoka vazduha smanjivao se prinos grube a istovremeno povećavao prinos fine frakcije. Grube frakcije suncokretove sačme dobijene pri protocima vazduha od 8,7 i 12,5 m³/h imale su za 0,5 &minus; 41,4% relativno veći sadržaj proteina u poređenju sa polaznom sačmom. Smanjenje POS i povećanje protoka vazduha uticalo je na povećanje, dok je povećanje JOVD, uticalo na smanjenje sadržaja proteina grube frakcije. Najveći sadržaj proteina (50,90%SM) imala je gruba frakcija suncokretove sačme dobijena pri sledećim parametrima: POS &minus; 1 mm; protok vazduha &minus; 12,5 m³/h; JOVD &minus; 30%. Na sadržaj proteina grube frakcije i odnos prinosa frakcija značajan uticaj (p &lt; 0,05) imali su POS čekidara i protok vazduha, dok je CFD model pokazao zadovoljavajuće poklapanje sa eksperimentalnim rezultatima. Cilj druge faze disertacije, faze ekstrudiranja, bio je najpre ispitivanje uticaja dodatka polazne suncokretove sačme (oko 37% proteina na SM) i njene dve visokoproteinske frakcije (oko 43% i 49% proteina na SM), dobijenih na osnovu odabranih parametara usitnjavanja i vazdu&scaron;ne klasifikacije, na postupak ekstrudiranja i fizički kvalitet ekstrudirane hrane za ribe. Maksimalno 20% ribljeg bra&scaron;na bilo je zamenjeno polaznom sunockretovom sačmom i njenim odabranim visokoproteinskim frakcijama, a njihov udeo u recepturi za ishranu pastrmke menjan je na osnovu dizajna sme&scaron;e. Za ekstrudiranje eksperimentalnih sme&scaron;a i dobijanje hrane u obliku granula kori&scaron;ćen je dvopužni ekstruder. Ulazni parametri ekstrudiranja bili su konstatni, osim sastava sme&scaron;e, a<br />praćeni su izlazni parametri ekstrudiranja: temperatura u cevi ekstrudera, temperatura<br />matrice, pritisak na matrici, specifična potro&scaron;nja energije (SME) i obrtni moment<br />elektromotora ekstrudera. Proizvedenim uzorcima ispitani su pokazatelji fizičkog kvaliteta: stepen ekspanzije, nasipna masa, tvrdoća, stepen otiranja, kapacitet upijanja ulja, nivo otpu&scaron;tanja ulja iz zauljenih granula, stabilnost u vodi i mikrostruktura granula. Prisutvo suncokretove sačme vi&scaron;eg sadržaja proteina i manjeg sadržaja celuloze u sme&scaron;i uticalo je na formiranje vi&scaron;e temperature matrice ekstrudera, kao i na smanjenje SME i obrtnog momenta. Povećanje sadržaja proteina suncokretove sačme doprinelo je stvaranju kompaktnije strukture granule, povećanju tvrdoće, otpornosti otiranju i stabilnosti granula u vodi, smanjenju nivoa otpu&scaron;tanja ulja, te je tako pozitivno uticalo na fizičke karakteristike granula. Visokoproteinska frakcija suncokretove sačme sa 49% proteina na SM doprinela je optimalnim fzičkim karakteristikama ekstrudirane hrane za pastrmku. Karakterizacija ove frakcije kao potencijalne nove sirovine u industriji hrane za ribe bio je krajnji cilj ispitivanja ove disertacije. U tu svrhu navedena frakcija suncokretove sačme poređena je u novom eksperimentu ekstrudiranja i ispitivanja fizičkog kvaliteta hrane za pastrmku sa ribljim bra&scaron;nom, kao i sojinim bra&scaron;nom, koje je najče&scaron;će kori&scaron;ćen izvor biljnih proteina u hrani za ribe. Kori&scaron;ćena je nova receptura sme&scaron;e ali ista postavka eksperimenta kao u prvom delu faze ekstrudiranja. Rezultati su pokazali da je prisustvo visokoproteinske suncokretove sačme sa oko 49% proteina (SM) doprinelo smanjenju temperature matrice, ali i povedanju SME i obrtnog momenta, a time i poroznosti granula &scaron;to je imalo pozitivan uticaj na kapacitet upijanja ulja granula, stabilnost granula i otpu&scaron;tanje nutrijenata u vodi, kao i negativan uticaj na stepen otiranja i nasipnu masu granula. Zamena 13,4% ribljeg bra&scaron;na u recepturi ovom viskoproteinskom frakcijom suncokretove sačme za rezultat je imala granule zadovoljavajućeg fizičkog kvaliteta. Granule najboljeg fizičkog kvaliteta dobijene su<br />kombinacijom visokoproteinske frakcije suncokretove sačme sa sojinim bra&scaron;nom, te se<br />moglo zaključiti da se funkcionalne karakteristike ove dve sirovine odlično dopunjuju, i da visokoproteinska frakcija suncokretove sačme, sa stanovi&scaron;ta tehnolo&scaron;kog kvaliteta hrane za ribu, predstavlja dobru alternativu ribljem bra&scaron;nu.</p> / <p>High price and finite availability of fish meal (FM), due to high expansion of aquaculture<br />sector in recent decades, are main concerns for modern day aquafeed industry. Partially or completely substation of fish meal in fish feed with protein sources of plant origin, together with finding novel alternative protein sources, is commonly used approach that enables sustainability of aquafeed industry in decades to come. New, relatively simple and low-cost procedure for dry fractionation of sunflower meal (SFM) was proposed within this thesis, with aim for producing high protein SFM fractions as a potential plant source alternative for FM in fish feed. Thus, thesis&rsquo;s researches were done in two phases, where the aim of the first phase, air classification phase, was to investigate the possibility of applying combination of grinding by hammer mill and air classification of ground SFM using gravitational, cascade air classifier (zigzag), in order to obtain protein enriched fractions. Independent variables of grinding and air classification were sieve openings diameter (SOD) of hammer mill (3, 2 and 1 mm), air flow (5, 8.7 and 12.5 m3/h) and bowl feeder oscillation rate (BFOR) of air classifier (30, 60 and 90% of the maximum). Depended responses were protein content and yield of obtained fractions. The experimental data were obtained using 3 x 3 x 3 full factorial experimental design according to response surface methodology (RSM). For the optimization of grinding and air classification, in order to obtain fraction with highest possible protein content and in high yield, regression analysis, principal component analysis (PCA), analysis of variance (ANOVA) and computational fluid dynamics (CFD) approach were employed. Zigzag air classifier was successfully used for fractionation of ground SFM into coarse and fine fraction. Yield of coarse fractions was decreasing, while fine fractions yield was increasing with the increase of the air flow. Coarse fractions of SFM obtained at 8.7 and 12.5 m3/h were 0.5 &minus; 41.4% relatively enriched in protein content compared to the starting SFM. Decrease of SOD and increase of air flow resulted in coarse fraction protein content increase, while increasing BFOR decreased coarse fraction protein<br />content. The coarse SFM fraction with highest protein content was obtained for the SFM<br />ground by 1 mm SOD, air flow of 12.5 m3/h, with BFOR set at 30%. Protein content of<br />coarse fraction and ratio of fractions yields were significantly affected (p &lt; 0.05) by SOD of hammer mill and air flow. CFD model coincide with the experimental results of air<br />classification. The first aim of second phase, extrusion phase, was to investigate influence of starting SFM (37% of protein at DM) and its two high protein fractions (43% and 49% of protein at DM), obtained by grinding and air classification, on extrusion process and physical quality of extruded fish feed. Maximum 20% of FM was substituted with SFM and its high protein fractions in trout feed recipe, and their share was changed according to the<br />mixture design. Twin screw extruder was used for the production of trout feed samples.<br />Primarily extrusion parameters were constant, except dry mixture composition, and<br />secondary extrusion factors were observed: extruder barrel&rsquo;s temperatures, temperature<br />and pressure at the die, specific mechanical energy (SME) and motor load as torque.<br />Selected physical properties of extruded trout feed samples were determined: radial<br />expansion, bulk density, hardness, durability, oil absorption capacity, oil leakage, water<br />stability and microstructure of feed. SFM higher in protein and lower in fiber influenced<br />higher die temperature and lower SME and torque during extrusion process. Increase in<br />protein content of SFM resulted in more compact structure of pellets, increased hardness, durability and water stability, decreased oil leakage and thus positively influenced on physical properties of feed. High protein SFM fraction with around 49% of protein (DM) contributed to the optimal physical properties of experimental feed and characterization of this SFM fraction, as a potential new raw material in fish feed industry, was definite aim of this thesis. Towards that, new set of experiments was conducted, where high protein SFM fraction was compared with FM and soybean flour (SBF) by extruding new samples of trout feed and investigating their physical quality. Results of second extrusion experiment showed that presence of high protein SFM fraction (49% of protein DM) in dry mixture decreased die temperature, while increased SME and torque, and with that also increased porosity of pellets, oil absorption capacity and water stability but decreased bulk density and durability. Substitution of 13.4% FM by high protein SFM fraction resulted in pellets with satisfactory physical quality. The highest quality pellets were obtained in combination of high protein SFM and SBF, which lead to the conclusion that functional characteristics of high protein SFM fraction and SBF are complementary, and that novel SFM, from the point of technical quality, presents good FM alternative.</p>

Le thème central de cette thèse est le plongement des espaces métriques dans les espaces de Banach. Les principaux plongements étudiés sont les plongements grossiers, uniformes ou Lipschitziens. On considère des questions concernant le plongement Lipschitzien de certaines classes d'espaces métriques, notamment les espaces métriques localement finis ou plus généralement les sous-ensembles localement finis des espaces de Banach Lp, avec 1<= p <= [infini]. Ces questions sont étroitement liées à la classification Lipschitzienne des espaces de Banach. Les plongements grossiers sont un outil clé pour l'étude de plusieurs conjectures célèbres (conjecture de Baum-Connes grossière, conjecture de Novikov grossière...). On mène alors une étude détaillée du plongement grossier, mais aussi uniforme, des espaces métriques propres dans les espaces de Banach sans cotype. Un troisième thème concerne ce qui est appelé le “programme de Ribe” par Manor Mendel et Assaf Naor. Cela consiste en la recherche d'invariants métriques qui caractérisent des propriétés locales des espaces de Banach. Dans cette optique on étudie le plongement de certains arbres.

Dry etching is an important technique for pattern transferin fabrication of most opto-electronic devices, since it canprovide good control of both structure size and shape even on asub-micron scale. Unfortunately, this process step may causedamage to the material which is detrimental to deviceperformance. It is therefore an objective of this thesis todevelop and investigate low damage etching processes for InPbased devices. An ion beam system in combination with hydrocarbon (CH4) based chemistries is used for etching. At variousion energies and gas flows the etching is performed in twomodes, reactive ion beam etching (RIBE) and chemical assistedion beam etching (CAIBE). How these conditions affect both etchcharacteristics (e.g. etch rates and profiles, surfacemorphology and polymer formation) and etch induced damage (onoptical and electrical properties) is evaluated and discussed.Attention is also paid to the effects of typical post etchingtreatments such as annealing on the optical and electricalproperties. An important finding is the correlation betweenas-etched surface morphology and recovery/degradation inphotoluminescence upon annealing in PH3. Since this type of atmosphere is typical forcrystal regrowth (an important process step in III/Vprocessing) a positive result is imperative. A low ion energy N2/CH4/H2CAIBE process is developed which not onlysatisfies this criteria but also exhibits good etchcharacteristics. This process is used successfully in thefabrication of laser gratings. In addition to this, the abilityof the ion beam system to modify the surface morphology in acontrollable manner is exploited. By exposing such modifiedsurfaces to AsH3/PH3, a new way to vary size and density of InAs(P)islands formed on the InP surfaces by the As/P exchangereaction is presented. This thesis also proposes a new etch chemistry, namelytrimethylamine ((CH3)3N or TMA), which is a more efficient methyl sourcecompared to CH4because of the low energy required to break the H3C-N bond. Since methyl radicals are needed for theetching it is presumably a better etching chemistry. A similarinvestigation as for the CH4chemistry is performed, and it is found that bothin terms of etch characteristics and etch induced damage thisnew chemistry is superior. Extremely smooth morphologies, lowetch induced damage and an almost complete recovery uponannealing can be obtained with this process. Significantly,this is also so at relatively high ion energies which allowshigher etch rates. <b>Keywords:</b>InP, dry etching, ion beam etching, RIBE,CAIBE, hydrocarbon chemistry, trimethylamine, As/P exchangereaction, morpholoy, low damage, AFM, SCM, annealing

<p>Dry etching is an important technique for pattern transferin fabrication of most opto-electronic devices, since it canprovide good control of both structure size and shape even on asub-micron scale. Unfortunately, this process step may causedamage to the material which is detrimental to deviceperformance. It is therefore an objective of this thesis todevelop and investigate low damage etching processes for InPbased devices.</p><p>An ion beam system in combination with hydrocarbon (CH₄) based chemistries is used for etching. At variousion energies and gas flows the etching is performed in twomodes, reactive ion beam etching (RIBE) and chemical assistedion beam etching (CAIBE). How these conditions affect both etchcharacteristics (e.g. etch rates and profiles, surfacemorphology and polymer formation) and etch induced damage (onoptical and electrical properties) is evaluated and discussed.Attention is also paid to the effects of typical post etchingtreatments such as annealing on the optical and electricalproperties. An important finding is the correlation betweenas-etched surface morphology and recovery/degradation inphotoluminescence upon annealing in PH₃. Since this type of atmosphere is typical forcrystal regrowth (an important process step in III/Vprocessing) a positive result is imperative. A low ion energy N₂/CH₄/H₂CAIBE process is developed which not onlysatisfies this criteria but also exhibits good etchcharacteristics. This process is used successfully in thefabrication of laser gratings. In addition to this, the abilityof the ion beam system to modify the surface morphology in acontrollable manner is exploited. By exposing such modifiedsurfaces to AsH₃/PH₃, a new way to vary size and density of InAs(P)islands formed on the InP surfaces by the As/P exchangereaction is presented.</p><p>This thesis also proposes a new etch chemistry, namelytrimethylamine ((CH₃)₃N or TMA), which is a more efficient methyl sourcecompared to CH₄because of the low energy required to break the H₃C-N bond. Since methyl radicals are needed for theetching it is presumably a better etching chemistry. A similarinvestigation as for the CH₄chemistry is performed, and it is found that bothin terms of etch characteristics and etch induced damage thisnew chemistry is superior. Extremely smooth morphologies, lowetch induced damage and an almost complete recovery uponannealing can be obtained with this process. Significantly,this is also so at relatively high ion energies which allowshigher etch rates.</p><p><b>Keywords:</b>InP, dry etching, ion beam etching, RIBE,CAIBE, hydrocarbon chemistry, trimethylamine, As/P exchangereaction, morpholoy, low damage, AFM, SCM, annealing</p>