A gel is a cross-linked polymer network that spans an entire liquid medium; its properties depend strongly on the interaction of the polymer and the liquid medium. There are various ways to induce gelation in different systems such as altering temperature or pH. In this study, phenol extracted protein fractions from non-acclimated (NA) and cold-acclimated (CA) winter rye (Secale cereale L. cv Musketeer) leaf tissue were subjected to freeze-thaw treatment. Gelation was induced in the NA and CA extracts after repeated freeze-thaw treatments, accompanied by a change in sample rheological properties. Further experimentation revealed that gel formation only occurred at high pH (pH 12.0) and that a minimum of 3 to 4 freeze-thaw cycles were required. The viscosity of the protein gel increased 5.7- to 9.5-fold in the NA and CA extracts respectively upon freeze-thaw. Experiments optimizing the extraction conditions and protein concentration were also performed. The gel was stable and only a specific combination of chaotropic agent, anionic surfactant and reducing agent such as urea, sodium docecyl sulfate (SDS) and â-mercaptoethanol (â-ME) with heating could disrupt the gel network. The gel was composed of several proteins in the extracts as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Based on SDS-PAGE analysis, ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) was identified as the major protein component in the gel. Various experiments were performed to assess the role of Rubisco in gel formation; however, the results were inconclusive. It is suggested that these extracts may contain antifreeze proteins (AFPs) that have been demonstrated to form amyloid gels upon freeze-thaw. Further studies examining the composition and mechanism of gel formation may result in a future role for this material in the food industry.

A gel is a cross-linked polymer network that spans an entire liquid medium; its properties depend strongly on the interaction of the polymer and the liquid medium. There are various ways to induce gelation in different systems such as altering temperature or pH. In this study, phenol extracted protein fractions from non-acclimated (NA) and cold-acclimated (CA) winter rye (Secale cereale L. cv Musketeer) leaf tissue were subjected to freeze-thaw treatment. Gelation was induced in the NA and CA extracts after repeated freeze-thaw treatments, accompanied by a change in sample rheological properties. Further experimentation revealed that gel formation only occurred at high pH (pH 12.0) and that a minimum of 3 to 4 freeze-thaw cycles were required. The viscosity of the protein gel increased 5.7- to 9.5-fold in the NA and CA extracts respectively upon freeze-thaw. Experiments optimizing the extraction conditions and protein concentration were also performed. The gel was stable and only a specific combination of chaotropic agent, anionic surfactant and reducing agent such as urea, sodium docecyl sulfate (SDS) and â-mercaptoethanol (â-ME) with heating could disrupt the gel network. The gel was composed of several proteins in the extracts as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Based on SDS-PAGE analysis, ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) was identified as the major protein component in the gel. Various experiments were performed to assess the role of Rubisco in gel formation; however, the results were inconclusive. It is suggested that these extracts may contain antifreeze proteins (AFPs) that have been demonstrated to form amyloid gels upon freeze-thaw. Further studies examining the composition and mechanism of gel formation may result in a future role for this material in the food industry.

In this study, two sample sets from Zeugma Archaeological Area had been examined. The sample Set I includes 7 sediment, 18 stone, 4 brick/roof tile, 9 mortar, 4 plaster samples and the sample Set II consists of 24 mural painting samples. Samples were examined to get their raw material characteristics, mineralogical and chemical compositions, and microstructural properties using various analytical techniques such as Optical Microscopy, XRD, FTIR, PED-XRF, SEM-EDX and Raman Spectroscopy. In addition, mikroclimatic monitorings for temperature and relative humidity were also performed in that area. Sediments were calcereous soils of Eocene. Rock types of stones were mainly limestone which had 3 subgroups: micritic, biomicritic and recrytallised micritic limestones. The source of the limestones should be from the local formation. The firing temperature of brick/roof tile samples were estimated as 800-850&deg / C. Binder of mortar samples were mainly lime. Aggregate materials of brick/roof tiles, mortars, plasters and mural paintings may come from the river deposites of Euphrates. Mural painting samples have one intonaco layer, and single or double arriccio layers. The mural painting technique was fresco technique. Calcite was common mineral identified for all pigments. The sources of white, black and green coloured pigments were found as vaterite, graphite and malachite respectively. The sources of yellow coloured pigments were identified as ankerite, siderite and goethite. The red colours were identified as hematite, jasper and red earth/ochre. Jasper and vaterite, jasper and calcite, red earth/ochre and calcite, and hematite were the colour forming minerals of pink coloured pigments.

Oxyborate minerals can represent the most important sink for boron in silica-undersaturated mineralised systems such as those of the Långban-type. Yet, their distribution, characteristics and parageneses are still not completely known. In order to test the hypothesis that the chemical compositions of oxyborates are essentially reflecting their local environments, the present study was set up. Additional observations regarding their assemblages, textures and structure would allow for a broader understanding of their formation and paragenetic interrelationships. A representative selection of Mg-(Fe-Mn) oxyborates and associated minerals have been characterised using optical microscopy, field emission electron probe microanalysis (FE-EPMA) with wavelength dispersive spectroscopy (WDS), and Raman spectroscopy. The studied samples are from a suite of carbonate-hosted Fe-Mn oxide deposits in the western part of the Palaeoproterozoic Bergslagen ore province, in south central Sweden and include the minerals blatterite [(Mn2+,Mg)35(Mn3+,Fe3+)9Sb5+3(BO3)16O32], fredrikssonite [Mg2(Mn3+,Fe3+)BO5], chemically variable ludwigites [c. (Mg,Fe2+)2Fe3+BO5], orthopinakiolite [(Mg,Mn2+)2Mn3+BO5] and pinakiolite [(Mg,Mn2+)2(Mn3+,Sb5+)BO5]. The results show a correlation between the cation distribution in the oxyborates fredrikssonite, ludwigite, orthopinakiolite as well as pinakiolite, and their associated metal oxides consisting of hausmannite and spinel group minerals. This combined with the textural relationships of the phases suggests that the bulk contents of magnesium, manganese and iron in the oxyborates were sequestered from these pre-existing metal oxides. The chemically broad range of hausmannite and spinel group minerals associated with specifically fredrikssonite and ludwigite agrees with their more frequent general occurrence, compared to orthopinakiolite and pinakiolite. Raman spectroscopy verified the structural character of the studied oxyborates and indicates a potential connection between the presence of manganese and whether local BO33- ions are allowed to be positioned in symmetry sites which result in a split E´ mode. The results from this study contribute to the understanding of this family of minerals and their potential diversity in mineralised systems, and form a fundamental prerequisite for their potential application for boron isotope studies. / Mineral är kemiska föreningar eller rena grundämnen som har en väldefinierad kemisk sammansättning, ordnad kristallstruktur och är bildade av geologiska processer. Oxyborater är en typ av sådana föreningar vilka innehåller grundämnena bor och syre samt olika kombinationer av metalliska grundämnen. Oxyboratmineral kan bland annat bildas i och omkring malmfyndigheter där grundämnet kisel är ovanligt eller icke förekommande, och kan utgöra de viktigaste borföreningarna i vissa sådana miljöer. Genom att bättre förstå denna typ av mineral och de kemiska och bildningsmässiga samband som finns mellan dem och andra föreningar kan vi få en större kunskap om hur de bildas, samt hur olika grundämnen kan omfördelas i sådana geologiska system. I denna studie har ett representativt urval av oxyborater undersökts med hjälp av mikroskopi och mikrokemiska samt spektroskopiska metoder för att testa huruvida deras kemiska sammansättning är direkt kopplad till den lokala miljön. De studerade proven kommer från karbonatbundna mineraliseringar i den västra delen av malmprovinsen Bergslagen i södra Mellansverige. De mineral som undersökts närmre är oxyboraterna blatterit, fredrikssonit, ludwigit, ortopinakiolit och pinakiolit. Resultaten visar på direkta kemiska samband mellan uppträdandet av fredrikssonit, ludwigit, ortopinakiolit samt pinakiolit, och de lokalt bergartsbildande mineral som de samexisterar med. Den breda kemiska fördelningen hos de metall- och syreföreningar som finns i samma omgivning som fredrikssonit och ludwigit förklarar också varför dessa två oxyborater generellt är mera vanligt förekommande än ortopinakiolit och pinakiolit. De spektroskopiska analyserna verifierar den tidigare klassificeringen av de studerade oxyboraterna samt visar på ett möjligt samband mellan innehållet av metallen mangan, samt hur grundämnet bor förekommer i deras kristallstruktur. Resultaten från denna studie bidrar med en kombination av nya kemiska, paragenetiska och spektroskopiska data samt ökar förståelsen av dessa värdmineral för grundämnet bor i malmfyndigheter med låg eller ingen kiselhalt. Resultaten ger även en insikt i hur den kemiska sammansättningen potentiellt kan påverka kristallstrukturen hos dessa oxyborater.