La peau est une interface essentielle entre le corps humain et son environnement externe. Au-delà du rôle de couche protectrice contre les agressions externes (mécaniques, thermiques, chimiques…), elle dispose de multiples fonctions de régulation comme l’absorption, la thermorégulation ou la synthèse d’hormones. L’étude de cette interface cutanée est importante, non seulement pour les spécialistes cliniques, mais également pour les chercheurs travaillant dans la compréhension des mécanismes des processus de transfert transcutanés. Longtemps considéré comme une simple couche de cellules mortes, le stratum corneum (SC, couche de la peau la plus externe) était considéré alors comme un acteur secondaire dans ces processus. Des études récentes montrent au contraire que cette couche cutanée, d’une épaisseur pouvant aller de 10 à 40 µm, joue un rôle primordial et déterminant. Ces études révèlent une architecture complexe, qui peut être représentée schématiquement par un empilement de cellules protéiniques (les cornéocytes) situées dans une matrice extracellulaire riche en lipides. Cette couche compacte est loin d’être complètement imperméable aux substances chimiques directement appliquées sur la peau. Nous proposons ici une approche physico-chimique visant à mettre en évidence les mécanismes d’interactions acide-base agissant à l’extrême surface du SC (i.e. une dizaine d’Angströms). En utilisant : i) les réactions de transfert de protons comme “sonde” et ii) une démarche multi-échelles basée sur des titrations de surface par angles de contact et par forces chimiques, nous déterminons quantitativement le rôle de chacune des composantes du SC (i.e. cornéocytes et lipides) dans ce type d’interactions. / Stratum corneum (SC) is a heterogeneous tissue composed of lipid-depleted corneocytes embedded in a lipid-enriched extracellular matrix. It comes from the epidermal differentiation of the skin. The wetting properties of this upper layer are of major interest in the understanding of interfacial phenomena, such as adhesion of microorganisms or proliferation of resident flora. Until now, the wettability behaviour has been characterized through different parameters such as surface energy, critical surface tension, or hydrophilia, via macroscopic contact angle measurements. But this method does not allow to discriminate the effect of the corneocytes with the one of the extracellular matrix on the final surface properties, because of the size of the liquid drop. This work, performed in vitro on human skin explants provided by Pierre Fabre Dermo-Cosmetics, consists in understanding the wetting properties of the SC from macroscopic and nanoscopic points of view. Initially, it is compulsory to thoroughly describe at different scales the physical chemistry of our material, i.e. in vitro SC. Then, knowing that macroscopic contact angles are sensitive to the pH of the liquid probe, the first aim of this work is to determine the “macroscopic pKa values” of the SC, both in vitro and in vivo. Consequently, dynamic contact angles are measured between test-liquid drops (aqueous solutions ranging from pH 1 to pH 13) and the SC in order to obtain the contact angle titration curve of the SC. The same procedure is applied in vivo on SC suffering from skin dryness (xerosis), the results being compared to those obtained previously on safe skin. The second purpose of this study is to reach the pKa values of the different functional groups located on the complex-cornified envelope. This consists in measuring adhesion forces between an AFM (Atomic Force Microscopy) tip (functionalized with specific groups, such as amine, carboxylic acid, hydroxyl, methyl or amide groups) and single-isolated corneocytes through buffered liquid media (ranging from pH 1 to pH 13). As previously, such titration curves are realised on corneocytes coming from safe skin, but also from dry skin. The variations observed in the contact angle titration and chemical force titration curves will be discussed in terms of acid-base, electrostatic interactions and hydrogen bondings. The comprehension of the pH-dependent properties of the SC shall provide a better understanding of the role of individual corneocytes in the final surface properties of the SC.

<p>Sa&nbsp; jedne&nbsp; strane&nbsp; se&nbsp; eksploatacija&nbsp; &scaron;ljunka&nbsp; navodi kao&nbsp; značajan&nbsp; ugrožavajući&nbsp; faktor&nbsp; sa&nbsp; velikim negativnim&nbsp; uticajem&nbsp; na&nbsp; vodena&nbsp; stani&scaron;ta&nbsp; i biodiverzitet,&nbsp; dok&nbsp; same&nbsp; &scaron;ljunkare&nbsp; mogu predstavljati&nbsp; vredne&nbsp; refugijume&nbsp; akavtičnog&nbsp; biodiverziteta.&nbsp; Osnovni&nbsp; cilj&nbsp; disertacije&nbsp; je određivanje&nbsp; najznačajnijih&nbsp; i&nbsp; relevantnih hidromorfolo&scaron;kih&nbsp; parametara&nbsp; koji&nbsp; utiču&nbsp; na strukturiranje&nbsp; makrofitskih&nbsp; zajednica&nbsp; u &scaron;ljunkarama&nbsp; duž&nbsp; plavnog&nbsp; područja&nbsp; reke&nbsp; Drine&nbsp; i određivanje&nbsp; korelacije&nbsp; između&nbsp; izdvojenih parametara&nbsp; i&nbsp; kvantitativnih&nbsp; indeksa&nbsp; makrofita.Istraživanje&nbsp; je&nbsp; vr&scaron;eno&nbsp; u&nbsp; toku&nbsp; letnjih&nbsp; meseci 2015, 2016, 2017 i 2018. godine na 18 &scaron;ljunkara (60 istraživačkih vegetacijskih sektora) u okviru tri&nbsp;&nbsp; eksploataciona&nbsp; polja&nbsp; u&nbsp; Crnoj&nbsp; Bari, Badovincima&nbsp; i&nbsp; Lipničkom&nbsp; &Scaron;oru&nbsp; i&nbsp; na&nbsp; četiri prirodna&nbsp; fluvijalna&nbsp; jezera&nbsp; (13&nbsp; istraživačkih vegetacijskih&nbsp; sektora)&nbsp; u&nbsp; plavnom&nbsp; području&nbsp; reke Drine.&nbsp; Makrofitska&nbsp; vegetacija&nbsp; je&nbsp; konstatovana na svih 18 istraţivanih &scaron;ljunkara, prikupljenih na tri eksploataciona polja (Badovinci, Crna Bara&nbsp; i<br />Lipniĉki &Scaron;or). Zabeležena je 31 biljna vrsta. Kao najučestalije,&nbsp; sa&nbsp; najvećom&nbsp; apsolutnom pokrovno&scaron;ću izdvojile su se vrste:&nbsp;<em> Potamogeton nodosus</em>&nbsp; Poiret,&nbsp; <em>Ceratophyllum&nbsp; demersum&nbsp; L subsp.&nbsp; demersum,&nbsp; Myriophyllum&nbsp; spicatum&nbsp; L,Najas&nbsp; marina&nbsp; L&nbsp; i&nbsp;&nbsp; Chara&nbsp; globularis&nbsp; Thuill&nbsp;</em> Na četiri prirodna fluvijalna jezera zabeleženo je 13 vrsta.&nbsp; Vrste&nbsp; <em>Vallisneria&nbsp; spiralis&nbsp; L,&nbsp; Elodea canadensis&nbsp; Michx,&nbsp; Callitriche&nbsp; palustris&nbsp; L, Potamogeton&nbsp; natans&nbsp; L&nbsp; i&nbsp; Nuphar&nbsp; lutea&nbsp; (L)&nbsp;</em> Sm izdvojile&nbsp; su&nbsp; se&nbsp; kao&nbsp; konstantne&nbsp; i&nbsp; dominantne. Vrednosti svih kvantitativnih indeksa makrofita,<br />značajno&nbsp; su&nbsp; veće&nbsp; za&nbsp; &scaron;ljunkare&nbsp; u&nbsp; poređenju&nbsp; sa prirodnim&nbsp; fluvijalnim&nbsp; jezerima&nbsp; na&nbsp; nivouLEAFPACS&nbsp; sektora.&nbsp; Na&nbsp; istraživanim &scaron;ljunkarama,&nbsp; analizom&nbsp; klasterovanja&nbsp; je<br />izdvojeno&nbsp; 13&nbsp; vegetacijskih&nbsp; grupa&nbsp; (VG):&nbsp; VG1<em> Ceratophyllum&nbsp; demersum</em>,&nbsp; VG2&nbsp; <em>Ceratophyllum demersum&nbsp; -&nbsp; Valisneria&nbsp; spiralis</em>,&nbsp; VG3&nbsp; <em>Chara contraria,</em>&nbsp; VG4&nbsp; <em>Chara</em>&nbsp; <em>globularis,</em>&nbsp; VG5&nbsp; <em>Elodea canadensis,</em>&nbsp; VG6&nbsp; <em>Elodea&nbsp; nuttallii</em>,&nbsp; VG7&nbsp; <em>Najas marina</em>,&nbsp; VG8&nbsp; <em>Najas&nbsp; minor,</em>&nbsp; VG9&nbsp; <em>Nitellopsis obtusa</em>,&nbsp; VG10&nbsp;<em> Nuphar&nbsp; lutea</em>,&nbsp; VG11 <em>Potamogeton&nbsp; nodosus</em>,&nbsp; VG12&nbsp;<em> Potamogeton natans&nbsp;</em> i&nbsp;&nbsp; VG13&nbsp; <em>Potamogeton&nbsp; pectinatus</em>.&nbsp; Na prirodnim&nbsp; fluvijalnim&nbsp; jezerima&nbsp; konstatovane&nbsp; su četiri&nbsp; vegetacijske&nbsp; grupe:&nbsp; VG5&nbsp;<em> Elodea canadensis</em>,&nbsp; VG10&nbsp; <em>Nuphar&nbsp; lutea,</em>&nbsp; VG12<em> Potamogeton natans&nbsp;</em> i&nbsp; VG14&nbsp; <em>Typha latifolia</em>.&nbsp; Na osnovu izmerenih fizičko-hemijskih parametara,kvalitet vode u većini &scaron;ljunkara odgovara II klasi kvaliteta, na osnovu čega se mogu okarakterisati kao&nbsp; vodna&nbsp; tela&nbsp; sa&nbsp; dobrim&nbsp; i&nbsp; boljim&nbsp; ekolo&scaron;kim potencijalom. Sve &scaron;ljunkare i fluvijalna jezera se klasifikuju&nbsp; kao&nbsp; visoko&nbsp; alkalna.&nbsp; Kvalitet&nbsp; vode&nbsp; u prirodnim&nbsp; fluvijalnim&nbsp; jezerima&nbsp; odgovara&nbsp; III&nbsp; &ndash; IV&nbsp; klasi&nbsp; kvaliteta&nbsp; voda,&nbsp; pri&nbsp; čemu&nbsp; se&nbsp; mogu okarakterisati&nbsp; kao&nbsp; vodna&nbsp; tela&nbsp; sa&nbsp; slabim&nbsp; do umerenim&nbsp; ekolo&scaron;kim&nbsp; statusom.&nbsp; Značajno&nbsp; veće<br />vrednosti&nbsp; ukupnih&nbsp; suspendovanih&nbsp; materija, hemijske&nbsp; i&nbsp; biolo&scaron;ke&nbsp; potro&scaron;nje&nbsp; kiseonika, ukupnog&nbsp; organskog&nbsp; kiseonika&nbsp; i&nbsp; nitrata zabeležene su na prirodnim fluvijalnim jezerima u poređenju sa &scaron;ljunkarama. Izmerene vrednosti fizičko-hemijskih&nbsp; parametara&nbsp; ukazuju&nbsp; na mezotrofni&nbsp; karakter&nbsp; lokaliteta&nbsp; u&nbsp; Badovincima&nbsp; i mezo-eutrofni&nbsp; karakter&nbsp; lokaliteta&nbsp; u&nbsp; Lipničkom &Scaron;oru,&nbsp; dok&nbsp; se&nbsp; &scaron;ljunkare&nbsp; na&nbsp; teritoriji&nbsp; Crne&nbsp; Bare mogu&nbsp; okarakterisati&nbsp; kao&nbsp; eutrofna&nbsp; jezera.Vrednosti&nbsp; LHMS&nbsp; (modifikacionog)&nbsp; skora&nbsp; za &scaron;ljunkare kretale su se u rasponu od 9&nbsp; &ndash;&nbsp; 15, dok su vrednosti LHQA skora (stani&scaron;nog diverziteta) bile u rasponu izmeĊu 33&nbsp; &ndash;&nbsp; 44. Sliĉne vrednosti za&nbsp; LHQA&nbsp; skor&nbsp; su&nbsp; izraĉunate&nbsp; i&nbsp; za&nbsp; prirodna fluvijalna&nbsp; jezera&nbsp; (36&nbsp; &ndash;&nbsp; 49).&nbsp; MeĊutim,&nbsp; vrednosti<br />LHMS&nbsp; skora&nbsp; za&nbsp; prirodna&nbsp; fluvijalna&nbsp; jezera&nbsp; su znaĉajno&nbsp; veće&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; vrednosti&nbsp; LHMS skora za &scaron;ljunkare. Ovi podaci ukazuju na manje prisustvo&nbsp; antropogenog&nbsp; pritiska&nbsp; na&nbsp; &scaron;ljunkarama u poređenju sa prirodnim fluvijalnim jezerima uistraţivanom&nbsp; podruĉju.&nbsp; Fizičko -hemijski&nbsp; i hidromorfolo&scaron;ki&nbsp; parametri&nbsp; zajedno&nbsp; su&nbsp; objasnili 57.07&nbsp; %&nbsp; od&nbsp; ukupne&nbsp; varijanse&nbsp; vegetacijskih podataka,&nbsp; sa&nbsp; 16.57&nbsp; %&nbsp; deljenog&nbsp; efekta.&nbsp; Fizičkohemijski&nbsp; parametri&nbsp; kvaliteta&nbsp; vode&nbsp; objasnili&nbsp; su 17.02&nbsp; %&nbsp; varijabilnosti&nbsp; u&nbsp; strukturi&nbsp; makrofitske vegetacije.&nbsp; Kao&nbsp; najsignifikantniji&nbsp; parametri<br />izdvojili&nbsp; su&nbsp; se:&nbsp; saturacija&nbsp; vode&nbsp; kiseonikom,ukupni&nbsp; organski&nbsp; ugljenik,&nbsp; povr&scaron;inski&nbsp; aktivne materije, temperatura, elektroprovodljivost, pH i ukpni&nbsp; alkalitet.&nbsp; Hidromorfolo&scaron;ki&nbsp; parametri&nbsp; su objasnili&nbsp; 23.48&nbsp; %&nbsp; varijabilnosti&nbsp; u&nbsp; strukturi makrofitske&nbsp; vegetacije.&nbsp; Kao&nbsp; najsignifikantnije varijable,&nbsp; izdvojile&nbsp; su&nbsp; se:&nbsp; struktura&nbsp; vegetacije&nbsp; u priobalnoj&nbsp; zoni,&nbsp; diverzitet&nbsp; prirodnih&nbsp; tipova stani&scaron;ta&nbsp; priobalne&nbsp; zone,&nbsp; prirodnost&nbsp; obale, diverzitet&nbsp; prirodnog&nbsp; supstrata&nbsp; litorala,masimalna dubina &scaron;ljunkara, povr&scaron;ina &scaron;ljunkara,indeks relativne dubine, udaljenost &scaron;ljunkara od glavnog&nbsp; reĉnog&nbsp; toka&nbsp; i&nbsp; starost&nbsp; &scaron;ljunkara. Hidrolo&scaron;ki&nbsp; parametri&nbsp; su&nbsp; objasnili&nbsp; 8.38&nbsp; % varijabilnosti u strukturi&nbsp; makrofitske vegetacije. Kao&nbsp; najsignifikantnije&nbsp; varijable,&nbsp; izdvojile&nbsp; su&nbsp; se broj plavnih talasa u vegetacionoj sezoni tokom godine u kojoj je vr&scaron;eno uzorkovanje vegetacije i broj plavnih talasa u prolećnom periodu za sve četiri&nbsp; godine.&nbsp; Ovi&nbsp; rezultati&nbsp; potvrđuju&nbsp; direktni destruktivni&nbsp; uticaj&nbsp; plavnih&nbsp; talasa&nbsp; na&nbsp; vodenu vegetaciju u vegetacionoj sezoni, kao i indirektni uticaj prolećnih poplava, usled uticaja na trofički status&nbsp; vode.&nbsp; Sumarno,&nbsp; &scaron;ljunkare&nbsp; u&nbsp; plavnom području&nbsp; reke&nbsp; Drine&nbsp; predstavljaju&nbsp; optimalno stani&scaron;te&nbsp; za&nbsp; razvoj&nbsp; retke&nbsp; i&nbsp; ugroţene&nbsp; makrofitske flore.&nbsp; Od&nbsp; ukupnog&nbsp; broja&nbsp; zabeleženih&nbsp; vrsta makrofita,&nbsp; 30&nbsp; %&nbsp; se&nbsp; kategori&scaron;e&nbsp; kao&nbsp; za&scaron;tićeno&nbsp; ili ugroženo na nacionalnom nivou.&nbsp; Značajno veće vrednosti&nbsp; konzervacionih&nbsp; indeksa&nbsp; ustanovljene su&nbsp; za&nbsp; &scaron;ljunkare&nbsp; u&nbsp; poređenju&nbsp; sa&nbsp; prirodnim fluvijalnim jezerima, &scaron;to ukazuje na njihov visok ekolo&scaron;ki&nbsp; potencijal.&nbsp; Ustanovljen&nbsp; je&nbsp; visok diverzitet&nbsp; prioritetnih&nbsp; tipova&nbsp; akvatiĉnih&nbsp; stani&scaron;ta prema&nbsp; Pravilniku&nbsp; o&nbsp; kriterijumima&nbsp; za&nbsp; izdvajanje tipova&nbsp; stani&scaron;ta,&nbsp; o&nbsp; tipovima&nbsp; stani&scaron;ta,&nbsp; osetljivim, ugroženim,&nbsp; retkim&nbsp; i&nbsp; za&nbsp; za&scaron;titu&nbsp; prioritetnim tipovima&nbsp; stani&scaron;ta&nbsp; i&nbsp; o&nbsp; merama&nbsp; za&scaron;tite&nbsp; za&nbsp; njihovo očuvanje, Aneksu I, Direktive Evropske unije oza&scaron;titi&nbsp; prirodnih&nbsp; stani&scaron;ta&nbsp; i&nbsp; divlje&nbsp; flore&nbsp; i&nbsp; faune (Natura&nbsp; 2000),&nbsp; Rezoluciji&nbsp; br.&nbsp; 4&nbsp; Konvencije&nbsp; o očuvanju&nbsp; evropske&nbsp; divlje&nbsp; flore&nbsp; i&nbsp; faune&nbsp; i prirodnih&nbsp; stani&scaron;ta (EMERALD)&nbsp; i&nbsp; Evropskoj crvenoj&nbsp; listi&nbsp; stani&scaron;ta.&nbsp; Vrednosti&nbsp; izdvojenih atributa&nbsp; &scaron;ljunkara&nbsp; mogli&nbsp; bi&nbsp; se&nbsp; iskoristiti&nbsp; u procesu&nbsp; ranog&nbsp; planiranja&nbsp; i&nbsp; projektovanja eksploatacionih&nbsp; polja&nbsp; u&nbsp; plavnom&nbsp; području&nbsp; reke Drine&nbsp; i&nbsp; na&nbsp; drugim,&nbsp; sličnim&nbsp; lokalitetima. Generalna preporuka je da se dva tipa &scaron;ljunkara kreiraju&nbsp; u&nbsp; okviru&nbsp; jednog&nbsp; eksploatacionog&nbsp; polja. Prvi&nbsp; tip,&nbsp; odnosno&nbsp; &scaron;ljunkare&nbsp; koje&nbsp; bi&nbsp; podržavale pionirsku&nbsp; vegetaciju&nbsp; pr&scaron;ljenčica&nbsp; trebale&nbsp; bi&nbsp; da budu locirane na razdaljini do 100 m od glavnog rečnog&nbsp; toka,&nbsp; povr&scaron;ine&nbsp; do&nbsp; 1000&nbsp; m 2 i&nbsp; da&nbsp; imaju vrednost indeksa relativne dubine &gt; 5 %. Drugi tip&nbsp; &scaron;ljunkara&nbsp; koje&nbsp; bi&nbsp; podržavale&nbsp; vegetaciju karakterističnu&nbsp; za&nbsp; nizijska&nbsp; fluvijalna&nbsp; jezera trebale bi da budu locirane na razdaljani od oko 300 m od glavnog rečnog toka, dubine 3&nbsp; &ndash;&nbsp; 4&nbsp; m (najmanje 2 m), povr&scaron;ine između 10000 i 20000 m ²(najmanje&nbsp; 4000&nbsp; m² ),&nbsp; različitih&nbsp; vrednosti indeksa relativne dubine, ali&nbsp; ne preko 5 %. Sva eksploataciona&nbsp; polja&nbsp; bi&nbsp; trebalo&nbsp; isplanirati&nbsp; i isprojektovati&nbsp; kako&nbsp; bi&nbsp; se&nbsp; minimizirao&nbsp; uticaj&nbsp; na priobalnu&nbsp; i&nbsp; obalnu&nbsp; zonu.&nbsp; Pridržavanjem&nbsp; datih smernica&nbsp; povećao&nbsp; bi&nbsp; se&nbsp; diverzitet&nbsp; i&nbsp; kvalitet stani&scaron;ta,&nbsp; kao&nbsp; i&nbsp; konzervacioni&nbsp; potencijal &scaron;ljunkara. Kreiranjem &scaron;ljunkara na naĉin kao &scaron;to je predloženo u ovoj disertaciji omogućila bi se spontana&nbsp; rekultivacija&nbsp; eksploatacionih polja,odnosno&nbsp; remedijacija&nbsp; u&nbsp; cilju&nbsp; pobolj&scaron;anja kvaliteta vode i renaturalizacija stani&scaron;ta, čime bi se&nbsp; znatno&nbsp; smanjili,&nbsp; ili&nbsp; u&nbsp; potpunosti&nbsp; eliminisali, tro&scaron;kovi tehničke rekultivacije terena.</p> / <p>Gravel pit lakes in the river floodplains represent a kind of ecological paradox. Gravel exploitation was recognised&nbsp; as&nbsp; important&nbsp; factor&nbsp; significantlyaffecting&nbsp; aquatic&nbsp; habitats&nbsp; and&nbsp; biodiversity.&nbsp; On the&nbsp; other&nbsp; hand,&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; are&nbsp; valuable biodiversity&nbsp; refugiums,&nbsp; potentially&nbsp; supporting rarae&nbsp; species&nbsp; and&nbsp; habitats.&nbsp; The&nbsp; aim&nbsp; of&nbsp; this dissertation&nbsp; was&nbsp; to&nbsp; determine&nbsp; the&nbsp; most significant&nbsp; and&nbsp; relevant&nbsp; hydromorphological parameters&nbsp; in&nbsp; structuring&nbsp; macrophyte assemblages&nbsp; in gravel pit&nbsp; lakes along the Drina River floodplain and to determine the correlation between&nbsp; selected&nbsp; parameters&nbsp; and&nbsp; macrophyte quantitative&nbsp; indices.&nbsp; The&nbsp; research&nbsp; was&nbsp; carried out at the 18 gravel pit lakes (60 survey sectors) in&nbsp; Crna&nbsp; Bara,&nbsp; Badovinci&nbsp; and&nbsp; Lipnicki&nbsp; Sor&nbsp; and four natural fluvial lakes (13 survey sectors), in the&nbsp; Drina&nbsp; River&nbsp; floodplain&nbsp; during&nbsp; the&nbsp; summer months&nbsp; of&nbsp; 2015,&nbsp; 2016,&nbsp; 2017&nbsp; and&nbsp; 2018.Macrophyte&nbsp; vegetation&nbsp; was&nbsp; recorded&nbsp; in&nbsp; all&nbsp; 18 gravel pit lakes, in total supporting 31 taxa.&nbsp; The most&nbsp; abundant&nbsp; species,&nbsp; with&nbsp; highest&nbsp; tot al&nbsp; cover value&nbsp; were <em>Potamogeton</em>&nbsp; <em>nodosus,Ceratophyllum&nbsp;</em> demersum&nbsp; subsp.&nbsp; demersum,<em> Myriophyllum&nbsp; spicatum,&nbsp;</em> <em>Najas&nbsp; marina&nbsp;</em> and<em> Chara&nbsp; globularis</em>.&nbsp; Fluvial&nbsp; lakes&nbsp; supported&nbsp; 13 macrophyte&nbsp; taxa&nbsp; with&nbsp;<em> Vallisneria&nbsp; spiralis, Elodea&nbsp; canadensis,&nbsp; Callitriche&nbsp; palustris,Potamogeton&nbsp;</em> <em>natans&nbsp;</em> and&nbsp;<em> Nuphar&nbsp; lutea</em>&nbsp; as constant and dominant&nbsp; species.&nbsp; The values of all macrophyte&nbsp; quantitative&nbsp; indices&nbsp; found&nbsp; to&nbsp; be significantly&nbsp; higher&nbsp; in&nbsp; the&nbsp; gravel&nbsp; pit&nbsp; lakes compared&nbsp; to&nbsp; the&nbsp; fluvial&nbsp; ones.&nbsp; The&nbsp; cluster analysis&nbsp; revealed&nbsp; 14&nbsp; aquatic&nbsp; vegetation&nbsp; groups (VG).&nbsp; At&nbsp; 16&nbsp; out&nbsp; of&nbsp; 18&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; 13 vegetation&nbsp; groups&nbsp; were&nbsp; revealed:&nbsp; VG1<em>Ceratophyllum&nbsp; demersum</em>,&nbsp; VG2&nbsp; <em>Ceratophyllum demersum- Valisneria&nbsp; spiralis</em>,&nbsp; VG3&nbsp;<em> Chara contraria</em>,&nbsp; VG4&nbsp; <em>Chara&nbsp; globularis</em>,&nbsp; VG5&nbsp;<em> Elodea&nbsp; canadensis,</em>&nbsp; VG6&nbsp;<em> Elodea&nbsp; nuttallii,</em>&nbsp; VG7&nbsp; <em>Najas marina,&nbsp;</em> VG8&nbsp;<em> Najas&nbsp; minor,</em>&nbsp; VG9&nbsp; <em>Nitellopsis obtusa</em>,&nbsp; VG10&nbsp; <em>Nuphar&nbsp; lutea,</em>&nbsp; VG11 <em>Potamogeton&nbsp; nodosus</em>,&nbsp; VG12&nbsp; <em>Potamogeton natans,</em> VG13&nbsp;<em> Potamogeton pectinatus</em>), Natural fluvial&nbsp; lakes&nbsp; supported&nbsp; 4&nbsp; vegetation&nbsp; groups: VG5&nbsp; <em>Elodea&nbsp; canadensis</em>,&nbsp; VG10&nbsp; <em>Nuphar&nbsp; lutea</em>, VG12&nbsp; <em>Potamogeton&nbsp; natans&nbsp;</em> and&nbsp; VG14&nbsp;<em> Typha latifolia</em>.&nbsp; All&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; can&nbsp; be characterized&nbsp; as&nbsp; water&nbsp; bodies&nbsp; with&nbsp; good&nbsp; to maximal&nbsp; ecological&nbsp; potential,&nbsp; while&nbsp; all&nbsp; the fluvial ones can be characterized as water bidies with&nbsp; poor&nbsp; to&nbsp; moderate&nbsp; ecological&nbsp; status.&nbsp; The values&nbsp; of&nbsp; total&nbsp; suspended&nbsp; supstances,&nbsp; chemical and&nbsp; biological&nbsp; oxygen&nbsp; demand,&nbsp; total&nbsp; organic carbon&nbsp; and&nbsp; nitrates&nbsp; were&nbsp; significantly&nbsp; higher&nbsp; in the natural&nbsp; fluvial&nbsp; lakes compared to the gravel pit&nbsp; ones.&nbsp; Measured&nbsp; level&nbsp; of&nbsp; physico-chemical parameters&nbsp; indicating&nbsp; mesotrophic&nbsp; character&nbsp; of gravel&nbsp; pit&nbsp; lakes&nbsp; in&nbsp; Badovinci&nbsp; and&nbsp; mesoeutrophic&nbsp; in&nbsp; Lipnicki&nbsp; Sor,&nbsp; while&nbsp; all&nbsp; the&nbsp; gravel pits&nbsp; in&nbsp; Crna&nbsp; Bara&nbsp; could&nbsp; be&nbsp; characterized&nbsp; as eutrophic.&nbsp; Similar&nbsp; range&nbsp; values&nbsp; were&nbsp; calculated for&nbsp; LHQA&nbsp; for&nbsp; gravel&nbsp; pit&nbsp; and&nbsp; fluvial&nbsp; lakes&nbsp; (36 &ndash; 49). However, natural lakes&nbsp; showed significantly higher&nbsp; values&nbsp; for&nbsp; LHMS&nbsp; score.&nbsp; The&nbsp; above mentioned,&nbsp; indicates&nbsp; higher&nbsp; anthropogenic pressures&nbsp; on&nbsp; natural&nbsp; fluvial&nbsp; lakes&nbsp; compared&nbsp; to gravel&nbsp; pit&nbsp; ones.&nbsp; Physico-chemical&nbsp; and hydromorphological&nbsp; parameters&nbsp; together explained&nbsp; about&nbsp; 57&nbsp; %&nbsp; of&nbsp; the&nbsp; total&nbsp; variance&nbsp; of macrophyte&nbsp; assemblages&nbsp; with&nbsp; 16.57&nbsp; %&nbsp; of&nbsp; the shared effect. After accounting for the effects of physico-chemical&nbsp; parameters&nbsp; (17.02&nbsp; %), hydromorphological&nbsp; variables&nbsp; explained&nbsp; around 23 % of the total variance.&nbsp; The most significant water&nbsp; quality variables&nbsp; were: oxygen saturation, total&nbsp; organic&nbsp; carbon,&nbsp; surfactants, ,electroconductivity,&nbsp; pH&nbsp; and total alkalinity. The The most significant hydromorphology&nbsp; variables for&nbsp; structuring&nbsp; macrophyte&nbsp; assemblages&nbsp; were: riparian&nbsp; vegetation&nbsp; structural&nbsp; complexity, diversity&nbsp; of&nbsp; natural&nbsp; landcover&nbsp; types&nbsp; in&nbsp; riparianzone, shore structural habitat&nbsp; diversity, diversity of&nbsp; natural littoral zone, maximal&nbsp; lake depth, lake surface&nbsp; area,&nbsp; relative&nbsp; depth&nbsp; ratio,&nbsp; lake&nbsp; distance from&nbsp; r iver&nbsp; main&nbsp; channel&nbsp; and&nbsp; lake&nbsp;&nbsp; age.Hydrologycal parameters were explained 8.38 % of&nbsp; variance&nbsp; in&nbsp; structuring&nbsp; macrophyte assemblages.&nbsp; The&nbsp; most&nbsp; significant&nbsp; hydrology variables&nbsp; were&nbsp; the&nbsp; number&nbsp; of&nbsp; floods&nbsp; in vegetation&nbsp; season&nbsp; in&nbsp; first&nbsp; year&nbsp; when&nbsp; vegetation was sampled, and the number of spring floods in all four research years. These results&nbsp;&nbsp; confirm the direct destructive influence of summer floods&nbsp; on aquatic vegetation, as&nbsp;&nbsp; well as the indirect impact of&nbsp; spring&nbsp; floods,&nbsp; due&nbsp; to&nbsp; the&nbsp; impact&nbsp; on&nbsp; trophic status&nbsp; of&nbsp; water.&nbsp; Gravel&nbsp; pit&nbsp; lakes&nbsp; in&nbsp; te&nbsp; Drina River floodplain&nbsp; represent an optimal habitat&nbsp;&nbsp; for rare&nbsp; and&nbsp; threatened&nbsp; macrophyte&nbsp; flora.&nbsp; Of&nbsp; the total&nbsp; macrophyte&nbsp; species&nbsp; recorded,&nbsp; 30&nbsp; %&nbsp; were categorized&nbsp; as&nbsp; protected&nbsp; or threatened.&nbsp; At&nbsp; least one&nbsp; strictly&nbsp; protected,&nbsp; protected&nbsp; or&nbsp; threatened species&nbsp; was&nbsp; recorded&nbsp; in&nbsp; each&nbsp; gravel&nbsp; pit&nbsp; lake. Significantly&nbsp; higher&nbsp; values&nbsp; of&nbsp; conservation indices&nbsp; (C&nbsp; and&nbsp; Csp&nbsp; score)&nbsp; found&nbsp; to&nbsp; be significantly&nbsp; higher&nbsp; in&nbsp; the&nbsp; gravel&nbsp; pit&nbsp; lakes compared&nbsp; to&nbsp; the&nbsp; fluvial&nbsp; ones.&nbsp; High&nbsp; habitat diversity&nbsp; and&nbsp; conservation&nbsp; value&nbsp; of&nbsp; the&nbsp; sites have&nbsp; been&nbsp; recorded&nbsp; according&nbsp; to&nbsp; the&nbsp; National Rulebook,&nbsp; Annex&nbsp; I&nbsp; of&nbsp; Habitats&nbsp; Directive (NATURA 2000), Resolution&nbsp; no. 4 of the Bern Convention (EMERALD) and the European Red List&nbsp; of&nbsp; Habitats.&nbsp; Values&nbsp; of&nbsp; selected&nbsp; lake attributes can be used for early-design phases of future&nbsp; gravel&nbsp; extraction&nbsp; in&nbsp; the&nbsp; Drina&nbsp; River floodplain&nbsp; area,&nbsp; and&nbsp; in&nbsp; other&nbsp; similar&nbsp; sites. Therefore,&nbsp; general&nbsp; recommendations&nbsp; are&nbsp; that two gravel pit types should be excavated within the&nbsp; single&nbsp; extraction&nbsp; area&nbsp; in&nbsp; order&nbsp; to&nbsp; support pioneering charophyte vegetation and vegetation of typical eutrophic lowland floodplain lakes as well.&nbsp; The&nbsp; first&nbsp; hydromorphological&nbsp; lake&nbsp; type, suitable&nbsp; for&nbsp; stonewort&nbsp; species,&nbsp; should&nbsp; be excavated up to 100 m from river main channel, saving&nbsp; a&nbsp; surface&nbsp; area&nbsp; up&nbsp; to&nbsp; 1000&nbsp; m 2 and&nbsp; a relative depth ratio &gt; 5 %. The second gravel pit type&nbsp; should&nbsp; be&nbsp; located&nbsp; about&nbsp; 300&nbsp; m&nbsp; from&nbsp; river main channel, with preferable maximal depth inrange&nbsp; 3&ndash;4&nbsp; m&nbsp; (at&nbsp; least&nbsp; 2&nbsp; m&nbsp; depth),&nbsp; and&nbsp; a&nbsp; lake surface area between 10000 m 2 and 20000 m 2 (at least&nbsp; 4000&nbsp; m 2 ).&nbsp; Relative&nbsp; depth&nbsp; ratio&nbsp; may&nbsp; vary, but should be less than 5 %. Generally, all sites should&nbsp; be&nbsp; designed&nbsp; with&nbsp; the&nbsp; minimal&nbsp; impact to the&nbsp; riparian&nbsp; and&nbsp; shore&nbsp; zones.&nbsp; These&nbsp; proposed measures&nbsp; would&nbsp; considerably&nbsp; increase&nbsp; lake habitat diversity and their conservation potential. Creating&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; as&nbsp; proposed&nbsp; in&nbsp; this dissertation&nbsp;&nbsp;&nbsp; would&nbsp; allow&nbsp; spontaneous recultivation&nbsp; of&nbsp; exploitation&nbsp; fields,&nbsp; remediation in&nbsp; order&nbsp; to&nbsp; improve&nbsp; water&nbsp; quality&nbsp; and renaturalization&nbsp; of&nbsp; habitats,&nbsp; which&nbsp; will significantly reduce, or completely eliminate, the costs of terrain technical recultivation.</p>

Tiger nuts (Cyperus esculentus L) are recognized as a high potential, alternative source of food nutrients. However, there is limited scientific literature on the technological possibilities for developing value-added foods, such as fermented products from tiger nut milk. Therefore, strategies for producing and improving the properties of fermented tiger nut milk were investigated for generating lactose-free, nutritious yogurt-like products with acceptable sensory properties and a prolonged shelf life quality. A wet-milling procedure was standardized for extracting tiger nut milk from tiger nuts, and the effects of the extraction process on nutrient distribution, colour properties and colloidal stability of the milk were analyzed. Next, tiger nut milk was enriched with proteins and/or hydrocolloids and the impact of the additives on the physical properties of the milk were determined. Enriched tiger nut milk was fermented by using classical yogurt cultures and the obtained products were analyzed for the microbiological, physico-chemical and sensory characteristics. Additionally, effects of enriching tiger nut milk with microbial transglutaminase cross-linked proteins on the microbiological and physico-chemical properties were evaluated. Higher wet-milling intensity improved the nutrient composition, colloidal stability and colour of the milk. Enrichment of tiger nut milk with milk proteins and xanthan gum enhanced the viscosity and stability, and after fermentation, led to homogenous gel-like products with superior microbiological, physico-chemical and different sensory properties compared to the fermented plain tiger nut milk. Microbial transglutaminase cross-linked proteins improved the physical characteristics of the fermented product, especially during storage. This product would be relevant in many developing countries with high prevalence of lactose intolerance, limited access to nutritious food but show a high distribution of tiger nut vegetation.:1. Introduction and aim 1 2. Literature review 4 2.1 Tiger nut, origin, nutritional value and food use 4 2.2 Tiger nut milk, preparation and nutrient composition 7 2.3 Colloidal characteristics of tiger nut milk 9 2.4 Factors accounting for the dispersion stability of tiger nut milk 10 2.5 Enhancing tiger nut milk stability 12 2.6 Properties of fermented tiger nut milk 17 2.7 Microbial transglutaminase and properties of fermented tiger nut milk 18 3. Methodology 21 3.1 Extraction and characterisation of tiger nut milk 21 3.1.1 Sample collection and preparation 21 3.1.2 Tiger nut milk extraction 21 3.1.3 Nutrient analysis of tiger nuts 22 3.1.4 Analysis of tiger nut products 23 3.1.5 Particle size distribution 24 3.1.6 Colloidal stability 25 3.1.7 Colour measurement 25 3.2 Stabilisation of tiger nut milk dispersion 26 3.2.1 Tiger nut milk preparation 26 3.2.2 Preparation of tiger nut milk enrichments 26 3.2.3 Gravitational stability of enriched tiger nut milk 27 3.2.4 Accelerated gravitational stability of enriched tiger nut milk 28 3.2.5 Viscosity of TNM mixtures 29 3.3 Extraction and characterisation of globular tiger nut proteins 29 3.3.1 Protein extraction and fractionation 29 3.3.2 Molecular mass of globular tiger nut proteins 31 3.3.3 Denaturation temperature of globular tiger nut proteins 32 3.3.4 Isoelectric point of globular tiger nut protein 33 3.4 Properties of fermented tiger nut milk enriched with proteins 34 3.4.1 Materials and Reagents 34 3.4.2 Preparation of plain and enriched tiger nut milk 34 3.4.3 Fermentation of plain and enriched tiger nut milk 35 3.4.4 Viable counts of starter cultures in fermented tiger nut milk systems 36 3.4.5 Chemical analysis of unfermented and fermented tiger nut milk 36 3.4.6 Physical analysis of fermented tiger nut milk products 37 3.4.7 Sensory analysis of fermented tiger nut milk products 38 3.5 Microbial transglutaminase and fermented tiger nut milk property 38 3.5.1 Preparation of plain and enriched tiger nut milk 38 3.5.2 Fermentation of plain and enriched tiger nut milk 39 3.5.3 Analysis of the enzymatically cross-linked proteins 39 3.5.4 Viable counts 40 3.5.5 pH and titratable acidity 40 3.5.6 Syneresis and viscosity 41 3.5.7 Colour of fermented tiger nut products 41 3.6 Statistical analysis 41 4. Results and discussion 43 4.1 Extraction and characteristics of tiger nut milk 43 4.1.1 Material recovery, mass transfer and yield of tiger nut solids 43 4.1.2 Nutrient composition of tiger nut products 45 4.1.3 Physical properties of tiger nut milk 48 4.1.3.1 Particle size distribution of extracted tiger nut milk 48 4.1.3.2 Colloidal stability of tiger nut milk 49 4.1.3.3 Colour stability of tiger nut milk 51 4.2 Stabilisation of tiger nut milk 53 4.2.1 Effects of enrichments on the stability of tiger nut milk 53 4.2.2 Effects of pH and temperature on the stability of enriched TNM 56 4.2.3 Effects of enrichments on the rheology of tiger nut milk 58 4.3 Tiger nut protein extraction and characterisation 60 4.3.1 Protein extraction and fractionation 60 4.3.2 Molecular mass of tiger nut protein 62 4.3.3 Thermal denaturation of tiger nut protein 63 4.3.4 Isoelectric point of tiger nut proteins 66 4.4 Properties of fermented tiger nut milk enriched with proteins 67 4.4.1 Acidification and gel formation during fermentation 67 4.4.2 Microbiological properties of fermented enriched tiger nut milk 70 4.4.3 Physico-chemical properties of fermented enriched tiger nut milk 71 4.4.4 Sensory properties of fermented tiger nut milk products 76 4.5 Microbial transglutaminase and fermented tiger nut milk property 77 4.5.1 Effects on tiger nut milk fermentation 77 4.5.2 Microbiological properties during storage of fermented product 81 4.5.3 Physico-chemical properties during storage of fermented product 83 4.5.4 Effects on colour of fermented tiger nut product 86 5. Conclusions and outlook 88 Bibliography 90 List of figures 111 List of tables 115 List of Publications 116 Poster and presentations 116 / Erdmandeln (Cyperus esculentus L) haben ein hohes Potential als alternative Quelle Lebensmittelinhaltsstoffen. Allerdings gibt es nur in begrenztem Ausmaß Literatur über technologische Möglichkeiten zur Entwicklung von Mehrwert-Lebensmitteln wie fermentierter Erdmandelmilch. Daher wurden Strategien zur Herstellung und Verbesserung der Eigenschaften von fermentierter Erdmandelmilch zur Erzeugung laktosefreier joghurtähnlicher Produkte mit akzeptablen sensorischen Eigenschaften untersucht. Für die Extraktion der Erdmandelmilch wurde ein Nassmahlverfahren standardisiert und der Einfluss des Verfahrens auf die Nährstoffverteilung, die Farbeigenschaften und die kolloidale Stabilität der Milch analysiert. Als nächstes wurde Erdmandelmilch mit Proteinen und/oder Hydrokolloiden angereichert, und der Einfluss der Additive auf die physikalischen Eigenschaften des Extrakts bestimmt. Angereicherte Erdmandelmilch wurde mit klassischen Joghurtkulturen fermentiert, und die mikrobiologischen, physikalisch-chemischen und sensorischen Eigenschaften der Produkte wurden untersucht. Zusätzlich wurden Effekte der Anreicherung von Erdmandelmilch mit enzymatisch vernetzten Proteinen auf die mikrobiologischen und physikalisch-chemischen Eigenschaften bewertet. Eine höhere Nassmahlintensität verbesserte die Nährstoffzusammensetzung, die kolloidale Stabilität und die Farbe der Milch. Die Anreicherung erhöhte die Viskosität und Stabilität und führte nach der Fermentation zu homogenen gelartigen Produkten mit verbesserten mikrobiologischen, physikalisch-chemischen und sensorischen Eigenschaften im Vergleich zur fermentierten Erdmandelmilch. Mikrobielle Transglutaminase-vernetzte Proteine verbesserten die physikalischen Eigenschaften des fermentierten Produkts, insbesondere während der Lagerung. Dieses Produkt wäre in vielen Entwicklungsländern mit hoher Prävalenz von Laktoseintoleranz und begrenztem Zugang zu nahrhaften Lebensmitteln als Alternative von Interesse.:1. Introduction and aim 1 2. Literature review 4 2.1 Tiger nut, origin, nutritional value and food use 4 2.2 Tiger nut milk, preparation and nutrient composition 7 2.3 Colloidal characteristics of tiger nut milk 9 2.4 Factors accounting for the dispersion stability of tiger nut milk 10 2.5 Enhancing tiger nut milk stability 12 2.6 Properties of fermented tiger nut milk 17 2.7 Microbial transglutaminase and properties of fermented tiger nut milk 18 3. Methodology 21 3.1 Extraction and characterisation of tiger nut milk 21 3.1.1 Sample collection and preparation 21 3.1.2 Tiger nut milk extraction 21 3.1.3 Nutrient analysis of tiger nuts 22 3.1.4 Analysis of tiger nut products 23 3.1.5 Particle size distribution 24 3.1.6 Colloidal stability 25 3.1.7 Colour measurement 25 3.2 Stabilisation of tiger nut milk dispersion 26 3.2.1 Tiger nut milk preparation 26 3.2.2 Preparation of tiger nut milk enrichments 26 3.2.3 Gravitational stability of enriched tiger nut milk 27 3.2.4 Accelerated gravitational stability of enriched tiger nut milk 28 3.2.5 Viscosity of TNM mixtures 29 3.3 Extraction and characterisation of globular tiger nut proteins 29 3.3.1 Protein extraction and fractionation 29 3.3.2 Molecular mass of globular tiger nut proteins 31 3.3.3 Denaturation temperature of globular tiger nut proteins 32 3.3.4 Isoelectric point of globular tiger nut protein 33 3.4 Properties of fermented tiger nut milk enriched with proteins 34 3.4.1 Materials and Reagents 34 3.4.2 Preparation of plain and enriched tiger nut milk 34 3.4.3 Fermentation of plain and enriched tiger nut milk 35 3.4.4 Viable counts of starter cultures in fermented tiger nut milk systems 36 3.4.5 Chemical analysis of unfermented and fermented tiger nut milk 36 3.4.6 Physical analysis of fermented tiger nut milk products 37 3.4.7 Sensory analysis of fermented tiger nut milk products 38 3.5 Microbial transglutaminase and fermented tiger nut milk property 38 3.5.1 Preparation of plain and enriched tiger nut milk 38 3.5.2 Fermentation of plain and enriched tiger nut milk 39 3.5.3 Analysis of the enzymatically cross-linked proteins 39 3.5.4 Viable counts 40 3.5.5 pH and titratable acidity 40 3.5.6 Syneresis and viscosity 41 3.5.7 Colour of fermented tiger nut products 41 3.6 Statistical analysis 41 4. Results and discussion 43 4.1 Extraction and characteristics of tiger nut milk 43 4.1.1 Material recovery, mass transfer and yield of tiger nut solids 43 4.1.2 Nutrient composition of tiger nut products 45 4.1.3 Physical properties of tiger nut milk 48 4.1.3.1 Particle size distribution of extracted tiger nut milk 48 4.1.3.2 Colloidal stability of tiger nut milk 49 4.1.3.3 Colour stability of tiger nut milk 51 4.2 Stabilisation of tiger nut milk 53 4.2.1 Effects of enrichments on the stability of tiger nut milk 53 4.2.2 Effects of pH and temperature on the stability of enriched TNM 56 4.2.3 Effects of enrichments on the rheology of tiger nut milk 58 4.3 Tiger nut protein extraction and characterisation 60 4.3.1 Protein extraction and fractionation 60 4.3.2 Molecular mass of tiger nut protein 62 4.3.3 Thermal denaturation of tiger nut protein 63 4.3.4 Isoelectric point of tiger nut proteins 66 4.4 Properties of fermented tiger nut milk enriched with proteins 67 4.4.1 Acidification and gel formation during fermentation 67 4.4.2 Microbiological properties of fermented enriched tiger nut milk 70 4.4.3 Physico-chemical properties of fermented enriched tiger nut milk 71 4.4.4 Sensory properties of fermented tiger nut milk products 76 4.5 Microbial transglutaminase and fermented tiger nut milk property 77 4.5.1 Effects on tiger nut milk fermentation 77 4.5.2 Microbiological properties during storage of fermented product 81 4.5.3 Physico-chemical properties during storage of fermented product 83 4.5.4 Effects on colour of fermented tiger nut product 86 5. Conclusions and outlook 88 Bibliography 90 List of figures 111 List of tables 115 List of Publications 116 Poster and presentations 116

El propósito de esta tesis doctoral fue evaluar la influencia de los diferentes procesos de gestión de residuos, tales como la valorización material, energética y biológica de dos poliésteres clave de la industria del embalaje: el actual no-renovable poli (tereftalato de etileno) (PET) y el potencial candidato para sustituirlo en un futuro próximo, la polilactida (PLA) de base renovable. Se utilizaron diversas plantas piloto para simular las condiciones de la degradación sufrida por PET y PLA en el reciclado mecánico, la pirólisis, la combustión y el enterramiento en suelo. Los cambios fueron monitorizados por calorimetría diferencial de barrido (DSC), análisis dinámico-mecánico-térmico (DMTA), análisis termogravimétrico (TGA), espectrometría infrarroja con transformada de Fourier (FTIR), espectroscopia de correlación 2D-IR para el análisis de gases (EGA), espectrometría de masas MALDI-TOF, microscopía electrónica de barrido (SEM), índice de fluidez de masa fundida (MFR), ensayos de tracción e impacto Charpy y viscosimetría. Se han propuesto, desarrollado y aplicado diversas estrategias y procedimientos analíticos para establecer parámetros fiables para ser utilizados como indicadores de la degradación y por tanto controlar la influencia de cada proceso de valorización en la calidad del material. El comportamiento de PET y PLA reciclados mecánicamente se evaluó en base a sus propiedades químicas, microestructurales, mecánicas y térmicas. Se observó una pérdida general de prestaciones de PET y PLA reprocesado una vez y dos veces, respectivamente. Además, las propiedades de los materiales reciclados de PLA fueron mejores en términos relativos a los productos reciclados de PET. Las descomposiciones térmica y termo-oxidativa causadas por los procesos de pirolisis y combustión se evaluaron sobre la estabilidad térmica, gases emitidos y cinéticas de descomposición. Se destaca el uso de la combustión controlada para ambos polímeros, ya que se necesita menos energía para iniciar la descomposición, y la mezcla de gases que se desprenden es más homogénea. / Badía Valiente, JD. (2011). Strategies and analytical procedures for a sustainable plastic waste management. An application to poly (ethylene terephthalate) and polylactide in the packaging sector [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/12890 / Palancia

La pollution de l'environnement, et particulièrement la pollution atmosphérique et son possible impact sur la santé humaine, suscite un intérêt grandissant dans les pays en voie de développement. Ce travail de thèse s'inscrit dans cette thématique et constitue une étude pionnière en Afrique, et au Bénin plus particulièrement. Nos résultats ont montré que l'essence utilisée à Cotonou était de piètre qualité, caractérisée par l'absence d'additifs et par une forte concentration en benzène, et pouvait être à l'origine de la dégradation de la qualité de l'air de la ville. De même, l'analyse d'échantillons de particules (PM₂․₅ et PM>₂․₅) prélevés dans le quartier de St Michel à Cotonou, a mis en exergue un taux anormalement élevé de particules en suspension dans l'air. La caractérisation physicochimique de ces particules a montré la présence d'un cocktail de composés chimiques (ions, métaux, COVs, paraffines, HAPs, etc.), en proportion plus élevées dans les particules fines PM₂․₅. L'appareil respiratoire constituant la principale voie d'exposition de l'Homme à ces particules atmosphériques, leur potentiel toxique a été évalué au travers d'une étude in vitro menée sur des cellules épithéliales bronchiques humaines (BEAS-2B). Il a été ainsi démontré les propriétés cytotoxiques des deux échantillons de particules ainsi que leur capacité à induire l'expression génique des enzymes de métabolisation des composés organiques et à générer un stress oxydatif. Le déclenchement du processus inflammatoire via l'induction de l'expression génique et la sécrétion protéique de cytokines et l'apparition de modifications dans la voie de l'acide arachidonique (leucotriènes, prostaglandine, thromboxane) ont été notés. Enfin l'approche comparative des PM₂․₅ prélevées au niveau de trois villes d'Afrique de l'Ouest a permis de mettre en évidence des caractéristiques proches au Bénin, en Côte d'Ivoire et au Sénégal et la contribution des émissions du trafic routier dans la pollution de l'air. / Air pollution and its adverse health effects have shown a growing interest in developing countries. This study deals with this subject and is one of the first conducted in African countries, particularly in Benin. Our results showed that the quality of gasoline used in cotonou was poor, characterized by the absence of additive and a high concentration of benzene. Thus, it could be responsible for the degradation of the city air quality. Therefore, particulate matter samples (PM₂․₅ and PM>₂․₅) were collected in St Michel neighborhood at Cotonou and results showed very high levels of particles in the ambient air. Physicochemical characterization of these particles revealed a presence of various chemicals compounds (ions, metals, VOCs, paraffins, PAHs, ect.) in higher proportion in PM₂․₅ than PM>₂․₅. The respiratory system, the main way of exposure to these airborne particles, was investigated through an in vitro study assessing the toxic potential of PM on human bronchial epithelial cells (BEAS-2B). It has been demonstrated that the two types of particules have cytotoxic properties and ability to induce gene expression of organic compounds metabolizing enzymes and to generate oxidative stress. These particles have triggered the inflammatory process through the induction of gene expression and protein secretion of cytokines, and changes in the arachidonic acid pathway (leukotrienes, prostaglandin, and thromboxane). Finally, comparative approach for PM₂․₅ sampled in three West African cities highlighted the closeness of particles characteristics in Benin, Côte d'Ivoire and Senegal, and a significant contribution of road traffic emissions in the air pollution.

<p>Sir Isaac Newton’s famous discovery of gravity marks the rapid advancement of science in the English seventeenth century, and a permanent shift away from the scientific methods of antiquity. Natural philosophers were beginning to look at the physical world in new and dynamic ways. However, much of this new theory conflicted with traditional theology, which was problematic for Christian followers of this ‘new science’. To negotiate this conflict, a group of natural philosophers developed a new branch of science entitled physico-theology. This stream aims to prove that science does not dismiss religion, but is able to reinforce the existence of God and the truth of Biblical texts. John Woodward is a largely overlooked participant in physico-theology, but his literary works<em> </em>supply key information to modern readers in the understanding of this field. This study critically examines Woodward’s <em>Natural History of the Earth</em> for its significant contributions to early modern science and literary techniques of this discipline. This work is indicative of an emerging scientific method that aims to accommodate both physical observation and creative thinking. I argue that Woodward’s reliance on theology, while scientifically problematic, does not hinder his research, but is perversely productive by challenging him to pursue innovative hypotheses. This prominent, understudied text is remarkable for its fusion of science and theology, and for what it can illuminate about the interdependence of faith and reason in early modern science.</p> / Master of Arts (MA)

La thérapie cellulaire consiste à utiliser des cellules comme médicament injectable dans le but de favoriser la réparation d'un tissu ou d'un organe. Certaines cellules possèdent la propriété de stimuler la formation de nouveaux vaisseaux sanguins. Elles présentent un intérêt pour le développement d'un traitement des ischémies des membres inférieurs ou du myocarde. Déterminer le devenir de ces cellules après injection in vivo est important pour comprendre les mécanismes responsables de l'efficacité d'un tel traitement. Cependant, il est difficile à observer et très peu décrit dans la littérature. Quelques exemples d'utilisation de nanotechnologies sont rapportés pour suivre des cellules in vitro. Mais des facteurs limitant tels qu'une complexité de mise en oeuvre de ces techniques ou leur trop faible sensibilité rend difficile leur utilisation in vivo. Ce travail de thèse propose de décrire le développement de nanoparticules originales associant les modalités d'imagerie optique et d'IRM afin de marquer simplement des cellules ayant un potentiel thérapeutique. Les protocoles développés ont permis de vectoriser et suivre en temps réel ces cellules après injection chez la souris. / Cell therapy aims to use cells as injectable medicines in order to enhance damaged organs or tissues repair. Some cells have the ability to promote new blood vessels growth. Therefore, they have an interest in revascularization of ischemic tissues and are potential candidates for cell therapy in peripheral ischemia or myocardial infarction. Being able to determine these cell's fates after in vivo injection is a major step to better understand the mechanisms of such treatments efficiency. However, following this phenomenon is challenging and rarely described in scientific litterature. Only some applications of nanotechnologies to follow labeled cells in vitro have been published. But limitations as implementation complexity or a low sensitivity prevent from using these techniques in vivo. This phD work describes the development of new hybrids nanoparticules associating optical and magnetic resonance imaging modalities in order to efficiently label cells that have a therapeutic potential. Developed protocols allowed us to follow magnetic cell vectorisation after injection in mice in real time.

La thèse a pour but d’étudier les effets de changements de mouillabilité de roches dans des conditions d’injections d’eau douce en tant que méthode de récupération d’hydrocarbures. Afin d’identifier le ou les mécanismes à l’origine du gain additionnel de récupération nous avons utilisé un microtomographe RX. Nous avons ainsi imagé les états de saturations finales d’un milieu poreux rempli de saumures et d’huiles. Une fois le drainage primaire réalisé nous avons effectué deux phases d’imbibitions : avec une saumure (récupération secondaire) puis une imbibition d’eau douce (récupération tertiaire). L’analyse de la mouillabilité à l’échelle du pore a permis de mettre en évidence l’effet de la température et de la salinité sur la mouillabilité. Nous avons montré que les changements de mouillages des roches n’étaient pas occasionnées par la seule expansion de la couche électrique en revanche des changements de mouillabilité ont été montrés. Ces changements s’expliquant par des transitions de mouillages de second ordre observées non seulement pour des gouttes d’huiles sur de l’eau mais également sur un substrat en verre. Au final, la mouillabilité en milieux poreux doit être mise en évidence à une échelle sous-Micrométrique ce qui est relativement nouveau dans le domaine pétrolier. / The aim of the thesis is to study rock wettability change effects caused by Low Salinity brine injection as tertiary recovery method. To identify the underlying mechanism or mechanisms of additional oil recovery X-Ray imaging technology was applied. We have also imaged the end-Point saturations of filled by brine and water core samples. Once the primary drainage is realized we carried out two phases imbibitions: with high salinity brine (waterflooding) and with low salinity brine (tertiary recovery mode). The wettability analysis at pore scale permitted to put in evidence the thermal and saline effects playing a decisive role in rock wettability. We have showed wettability changes are not caused by only electrical double layer expansion, however wettability changes was shown. These changes are explained by wettability transition of second order and observed not only for oil droplet on brine, but also for oil deposited on glass substrate. Finally, the pore space wettability needs to be evidenced at sub-Micrometric scale that is new for the petroleum domain.

Ce manuscrit est consacré à l’étude et au développement de microsystèmes capteurs de gaz sélectifs au dioxyde d’azote, destinés au contrôle de la qualité de l’air atmosphérique. La stratégie que nous avons développée consiste à associer une structure sensible à base de matériaux semi-conducteurs partiellement sélectifs aux gaz oxydants et des filtres sélectifs à l’ozone. L’objectif premier est la mise en oeuvre et la caractérisation de matériaux chimiques strictement imperméables à l’ozone (O3) et non-réactifs vis-à-vis du dioxyde d’azote (NO2). Notre choix s’est focalisé sur un matériau moléculaire, l’indigo, connu pour sa réactivité vis-à-vis de O3, et plusieurs nanomatériaux carbonés. Pour ces derniers, la possibilité de conformer leurs textures, leurs morphologies et leurs chimies de surface par traitements thermiques, chimiques et mécaniques, permet d’étendre le panel de matériaux potentiels et d’identifier les facteurs d’influence de leur réactivité avec les espèces gazeuses. La caractérisation de l’ensemble de ces matériaux a nécessité l’utilisation de techniques adaptées et complémentaires (adsorption de N2 à 77 K, spectroscopies Raman, XPS, IR en mode ATR, RPE et NEXAFS). Les filtres chimiques les plus efficaces (hauts rendements de filtration et grande durabilité) ont été sélectionnés d’après des tests de soumission aux gaz selon une méthodologie adaptée. Enfin, l’association de ces meilleurs filtres et de la structure capteur a conduit à l’élaboration de prototypes microsystèmes capteurs de gaz optimisés. De plus, une contribution à la compréhension des mécanismes d’interaction de l’indigo et de certains nanocarbones avec O3 et NO2 a aussi permis d’améliorer le microsystème en développant des méthodologies pertinentes et innovantes mais également en réalisant la synthèse de nouveaux filtres indigo / nanocarbone. / This work is devoted to the study and the development of gas sensors microsystems highly selective to nitrogen dioxide, dedicated to the air quality control. The strategy developed consists in the implementation of a sensitive structure based on semiconductor materials partially selective to oxidizing gases associated to an ozone selective filter. The first objective is the development of chemical filters strictly impervious to ozone (O3) and non-reactive towards the nitrogen dioxide (NO2). We have chosen a molecular material, indigo, well-known for its reactivity towards O3, and several carbonaceous nanomaterials. For these one, the possibility to modify their textures, their morphologies and their surface chemistries by chemical, mechanical and thermic treatments, enables us to extend the range of potential materials and to identify the factors of influence on their reactivity with gaseous species. The characterization of all these materials required the use of appropriate and complementary techniques (N2 adsorption at 77 K, Raman, XPS, IR in ATR mode, EPR and NEXAFS). The more efficient filters (high filtering yield and life-time) have been selected by means of specific tests of gas exposure. Finally, the association of the best filter and the sensitive structure has led to the development of optimized gas sensors microsystems prototypes.

Le principal objectif de cette thèse était de mieux comprendre l’importance des Substances Polymériques Extracellulaires (SPE) dans la structuration et la formation des biofilms benthiques ; tout en s’inscrivant dans une étude plus globale des mécanismes écologiques impliqués dans le fonctionnement des vasières intertidales. La mise au point des dosages biochimiques a été effectuée sur le mucilage de l’algue Chaetomorpha aerea et a permis en parallèle de purifier un polysaccharide sulfaté riche en galactose, présentant une activité bactéricide sélective contre la souche Staphylococcus aureus (ATCC 25923). Les études biochimiques et écologiques menées sur les SPE extraits de la vasière charentaise ont ensuite permis de quantifier leur dynamique de production et leur composition, en fonction des conditions environnementales. La présence de désoxy-sucres et d’acides uroniques au sein des SPE capsulaires a laissé supposer que ces fractions jouaient un rôle important dans la formation et le devenir du biofilm microphytobenthique. La dernière partie des travaux a permis de caractériser les propriétés acide/base de Lewis et hydrophile/hydrophobe de la surface de la micro-algue Navicula jeffreyi, impliquée dans la formation de biofilms benthiques, par des méthodes classiques d’analyse. L’utilisation d’une nouvelle méthode, la Chromatographie Gazeuse Inverse (CGI), a permis d’obtenir des résultats intéressants et relativement similaires, confirmant le caractère prometteur de la CGI pour l’étude des propriétés de surface des micro-organismes. / The main goal of this thesis was to better understand the importance of Extracellular Polymeric Substances (EPS) in the structuring and formation of benthic biofilms; while considering a global conception of the ecological mechanisms involved in the functioning of intertidal mudflats. The development of the biochemical assays was done on the mucilage of the macroalgae Chaetomorpha aerea and allowed purifying a polysaccharide rich in galactose, showing a selective bactericidal activity against Staphylococcus aureus (ATCC 25923). Then, the biochemical and ecological studies concerning the EPS extracted from the local mudflat allowed studying their dynamic of production and composition in relation to environmental conditions. The presence of deoxy sugars and uronic acids in the bound EPS highlighted their important roles during the formation and the life of microphytobenthic biofilms. The last part of the work was used to characterize the acid/base of Lewis and hydrophilic/hydrophobic surface properties of the microalgae Navicula jeffreyi, involved in the formation of benthic biofilms, by using classical analysis methods. The use of a new method, named Inverse Gas Chromatography (IGC), allowed getting interesting and relatively similar results, confirming the potential of the method to study the surface properties of microorganisms.