X-ray diffraction analysis (XRD), infrared (IR) spectroscopy and scanning electron microscopy have been used for the characterization of cobalt-based pigments (Kremer Pigmente) and their lead-based glazes.It was also demonstrated that XRD analysis could be successfully used for the identification of cobalt pigments cobalt violet brilliant light CoNH4PO4•H2O, cobalt blue light, cerulean blue, cobalt green bluish CoO·ZnO in their glazes. However, only non-oxide cobalt pigments cobalt yellow [K3(Co(NO2)6]•3H2O, cobalt violet brilliant light and cobalt violet dark Co3(PO4)2 could be determined in their glazes using IR spectroscopy. The similarity of all SEM images of cobalt-based glazes let us to conclude, that the main morphological features of glazes are not dependent on the nature of cobalt pigment. The single phase cobalt violet light brilliant pigment has been synthesized using a simple co-precipitation approach. The characteristics of the obtained product were compared with those of a commercial sample purchased from Kremer Pigmente. For the first time to our knowledge, it was demonstrated that the characteristic Si-O absorption band at 812 cm-1 could be successfully used as indicator in the evaluation of molar ratio of CoO and SiO2 in their mixture. The novel method for the determination of SiO2 in physical mixtures of CoO ir SiO2 (in the range 9,1-50 %) or blue cobalt smalt pigment (CoO×nSiO2) (in the range 20-50 %) by FTIR spectroscopy is suggested. New cobalt-based... [to full text] / Atlikta istorinių kobalto pigmentų analogų Rentgeno spindulių difrakcinė analizė parodė, kad metodas efektyvus, nustatant kobalto šviesiai violetinį CoNH4PO4•H2O, kobalto mėlynąjį šviesų, ceruleumą ir kobalto žalsvai mėlyną CoO·ZnO, jų švino glazūrose, bet netinka aureolino [K3(Co(NO2)6]•3H2O, kobalto tamsiai violetinio Co3(PO4)2, kobalto mėlynojo tamsus, kobalto melsvai žalio ir smaltos CoO•nSiO2 nustatymui. IR spektroskopiniai tyrimai parodė, kad šis metodas efektyvus, kokybiškai nustatant neoksidinius kobalto pigmentus aureoliną, kobalto šviesiai violetinį, kobalto tamsiai violetinį jų švino glazūrose. Paprastu nusodinimo metodu susintetintas kobalto pigmentas violetinis šviesusis CoNH4PO4, pasižymintis analogiškomis fizikinėmis savybėmis, kaip ir komercinis Kremer Pigmente pigmentas. Sukurtas naujas, patogus ir pakankamai tikslus IR spektroskopinis SiO2 kiekio CoO ir SiO2 mišiniuose (ribose tarp 9,1-50 mol%) ir kobalto pigmente smaltoje CoO×nSiO2 (ribose tarp 20 iki 50 mol%) nustatymo metodas. Zolių-gelių metodu susintetinti ir visapusiškai ištirti nauji kobalto pigmentai: špinelio struktūros kobalto aliuminatas CoAl2O4 ir chromatas CoCr2O4 bei kobalto, aliuminio ir neodimio oksidų mišiniai (CoAl1,75Nd0,25O4, CoAl1,5Nd0,5O4, CoAlNdO4), pasižymintys spalvinėmis keraminių pigmentų savybėmis. Pirmą kartą zolių-gelių metodu susintetinti ir visapusiškai ištirti nauji kobalto pigmentai: vienfazis perovskito struktūros neodimio kobaltatas NdCoO3, mišrūs perovskitiniai neodimio... [toliau žr. visą tekstą]

In this dissertation, the results of detailed investigation of the seven unique art objects are presented. The presented results show that complex apllying of the instrumental analytical methods of OM, FTIR, SEM/EDX, XRD, μXRD and µRS is accurate and efficient way to identify composition of works of art and archaeological finds of glass, pigments or describe their technology. IR spectroscopy has been successfully applied to determine pigments and some pigment mixtures in painting‘s ground, paint layers, and destruction products in archaeological glass. The SEM/EDX analysis successfully can be used in determining the main elements of the paint samples at different cross-section points perform a qualitative analysis of the pigments (cinnabar, lead white, chalk, smalt et. al. ), in some cases, to discuss the features of the production of pigments. The SEM/EDX provided a possibility to examine three archaeological glass beads. According to the elemental composition, microstructure, and the specific features in different areas of the glass was defined nature of the destruction of glass. XRD and μXRD analysis successfully can be used in determining the crystalline phases in the paint and archaeological glass samples. Identify following pigments and their mixtures: calcite CaCO3, carbon, lead tin yellow type I Pb2SnO4, lead tin yellow type II PbSn03, hydrocerussite 2PbCO3 ∙ Pb (OH)2, cerussite PbCO3, Egyptian blue CaCuSi4O10, gypsum CaSO4 ∙ 2H2O, anhydrite CaSO4, huntite Mg3Ca(CO3)4... [to full text] / Septynių unikalių, didelę istorinę ir meninę vertę turinčių objektų – trijų XVII ir XVIII a. paveikslų, Senovės Egipto sarkofago bei trijų archeologinių stiklo karolių iš Kernavės-Kriveikiškių kapinyno – tyrimams sėkmingai pritaikyti OM, FTIR, SEM/EDX, XRD, μXRD ir µRS analizės metodai. Konstatuota, kad taikant kompleksinius tyrimus galima tiksliai ir efektyviai identifikuoti kūrinių medžiagas, charakterizuoti jų sandarą, apibūdinti technologijas. IR spektroskopija sėkmingai panaudota identifikuojant tapybos grunto ir dažų sluoksnių neorganinius tapybos pigmentus ir jų mišinius bei stiklo korozijos produktus. Parodyta, kad IR spektroskopija gali būti sėkmingai panaudota identifikuojant istorines restauravimo medžiagas. SEM/EDX analizės metodu nustatyta tapybos elementinė sudėtis, identifikuoti cinoberio, švino baltojo, kreidos, smaltos, suriko ir kt. pigmentai. SEM/EDX analizės metodu ištirti trys archeologiniai stiklo karoliai. Pagal elementinės sudėties skirtumus ir specifinius mikrostruktūros bruožus nustatytas stiklo destrukcijos pobūdis. XRD ir μXRD analizės metodais sėkmingai identifikuoti šie pigmentai ir/ar jų mišiniai: kalcitas CaCO3, anglis, I tipo Pb–Sn geltonasis Pb2SnO4, II tipo Pb–Sn geltonasis PbSn03, hidrocerusitas 2PbCO3∙Pb(OH)2, cerusitas PbCO3, Egipto mėlynasis CaCuSi4O10, gipsas CaSO4∙2H2O, anhidritas CaSO4, huntitas Mg3Ca(CO3)4, dolomitas CaMg(CO3)2. Pirmą kartą μRS metodu identifikuotas II tipo švino alavo geltonasis pigmentas, archeologiniam stiklui... [toliau žr. visą tekstą]

Septynių unikalių, didelę istorinę ir meninę vertę turinčių objektų – trijų XVII ir XVIII a. paveikslų, Senovės Egipto sarkofago bei trijų archeologinių stiklo karolių iš Kernavės-Kriveikiškių kapinyno – tyrimams sėkmingai pritaikyti OM, FTIR, SEM/EDX, XRD, μXRD ir µRS analizės metodai. Konstatuota, kad taikant kompleksinius tyrimus galima tiksliai ir efektyviai identifikuoti kūrinių medžiagas, charakterizuoti jų sandarą, apibūdinti technologijas. IR spektroskopija sėkmingai panaudota identifikuojant tapybos grunto ir dažų sluoksnių neorganinius tapybos pigmentus ir jų mišinius bei stiklo korozijos produktus. Parodyta, kad IR spektroskopija gali būti sėkmingai panaudota identifikuojant istorines restauravimo medžiagas. SEM/EDX analizės metodu nustatyta tapybos elementinė sudėtis, identifikuoti cinoberio, švino baltojo, kreidos, smaltos, suriko ir kt. pigmentai. SEM/EDX analizės metodu ištirti trys archeologiniai stiklo karoliai. Pagal elementinės sudėties skirtumus ir specifinius mikrostruktūros bruožus nustatytas stiklo destrukcijos pobūdis. XRD ir μXRD analizės metodais sėkmingai identifikuoti šie pigmentai ir/ar jų mišiniai: kalcitas CaCO3, anglis, I tipo Pb–Sn geltonasis Pb2SnO4, II tipo Pb–Sn geltonasis PbSn03, hidrocerusitas 2PbCO3∙Pb(OH)2, cerusitas PbCO3, Egipto mėlynasis CaCuSi4O10, gipsas CaSO4∙2H2O, anhidritas CaSO4, huntitas Mg3Ca(CO3)4, dolomitas CaMg(CO3)2. Pirmą kartą μRS metodu identifikuotas II tipo švino alavo geltonasis pigmentas, archeologiniam stiklui... [toliau žr. visą tekstą] / In this dissertation, the results of detailed investigation of the seven unique art objects are presented. The presented results show that complex apllying of the instrumental analytical methods of OM, FTIR, SEM/EDX, XRD, μXRD and µRS is accurate and efficient way to identify composition of works of art and archaeological finds of glass, pigments or describe their technology. IR spectroscopy has been successfully applied to determine pigments and some pigment mixtures in painting‘s ground, paint layers, and destruction products in archaeological glass. The SEM/EDX analysis successfully can be used in determining the main elements of the paint samples at different cross-section points perform a qualitative analysis of the pigments (cinnabar, lead white, chalk, smalt et. al. ), in some cases, to discuss the features of the production of pigments. The SEM/EDX provided a possibility to examine three archaeological glass beads. According to the elemental composition, microstructure, and the specific features in different areas of the glass was defined nature of the destruction of glass. XRD and μXRD analysis successfully can be used in determining the crystalline phases in the paint and archaeological glass samples. Identify following pigments and their mixtures: calcite CaCO3, carbon, lead tin yellow type I Pb2SnO4, lead tin yellow type II PbSn03, hydrocerussite 2PbCO3 ∙ Pb (OH)2, cerussite PbCO3, Egyptian blue CaCuSi4O10, gypsum CaSO4 ∙ 2H2O, anhydrite CaSO4, huntite Mg... [to full text]

Banana production ranks fifth behind cereals as a food crop and has potential, along with other major crops, to feed the world's increasing population. Globally, continuous efforts and techniques including the use of plant tissue culture (PTC) have been devised for increasing the production of several Musa species. The choice of cytokinin (CK) is one of the most critical factors in developing a successful PTC protocol. Since the discovery of topolins as naturally occurring aromatic CKs, they have emerged as genuine alternatives to the long serving CKs (benzyladenine = BA, zeatin = Z and kinetin = KIN) in PTC. Globally, the past 15 years has witnessed a surge in the use of topolins and their derivatives in research laboratories. Topolins have demonstrated great potential during culture initiation and protocol optimization as well as for counteracting various in vitro induced physiological disorders in some species. In terms of general physiology (growth, phytochemical and photosynthetic pigment contents as well as genetic fidelity), the topolins were compared with BA using 'Williams' bananas with minimal residual exogenous CK carry-over effects. The five topolins tested were meta-Topolin (mT); meta-Topolin riboside (mTR); meta-Methoxy topolin (MemT); meta-Methoxy topolin riboside (MemTR) and meta-Methoxy topolin 9-tetrahydropyran-2-yl (MemTTHP). Based on evidence of potential CK- and auxin-like activity of smoke-water (SW) and karrikinolide (KAR1) at low concentrations, a similar comparative study involving both compounds and mT was performed. For a further understanding of banana physiology in vitro, the effect of supplementing either mT- or BA-requiring cultures with roscovitine (a cyclin-dependent kinase and N-glucosylation inhibitor) and INCYDE (an inhibitor of CK degradation) on the endogenous CK profiles was investigated. In addition, greenhouse experiments geared towards improving the acclimatization competence of tissue-cultured banana plantlets via application of different concentrations of SW and vermicompost leachate was conducted. Sterile shoot-tip explants were cultured on modified Murashige and Skoog (MS) media supplemented with 10, 20 or 30 μM of the tested CKs for 42 days while rooting experiments involved the use of classic auxins as well as SW and KAR1. Apart from 10 μM BA and 30 μM MemTTHP treatments, the number of shoots produced with all the CK treatments were significantly higher than the control. Treatment with 30 μM mT resulted in the highest number of shoots (7.3±1.0) which is an indication of the requirement of exogenous CK for increased shoot proliferation in 'Williams' bananas The use of 10 μM MemTTHP had the least root inhibitory effect during the shoot proliferation phase. As an indication of the toxicity of applied CK, MemT- and MemTR-regenerants were the most deformed while mTR-regenerated plantlets demonstrated the best quality across all the CKs tested. In mT- and BA-derived shoots, SW and KAR1 significantly increased the number and length of roots compared to the control. During the rooting phase, topolin treatments produced more off-shoots than BA-treated ones which inevitably improved the overall number of regenerated shoots. Total phenolic levels were highest in 10 μM mT- and 30 μM MemTTHP-treated plantlets detected in the aerial and underground parts, respectively. It is interesting that in the underground parts, 10 μM mT resulted in the production of the highest amount of proanthocyanidins which was approximately five-fold higher than in the control plants. On the other hand, 10 μM MemTTHP-treated plantlets had significantly higher total flavonoids within the aerial parts. In view of the stimulation of secondary metabolites in the majority of the CK-treated plantlets, the current results indicate the role of the type and concentration of applied CK as potential elicitors in PTC. Generally, the maximum photosynthetic pigment content was attained between 40-50 days. The control plantlets had the highest pigment content (1150 μg/g FW) while 10 μM MemTTHP had the best pigment stimulatory effect among the tested CKs. Nevertheless, in vitro propagation of banana devoid of CKs is not a practical option due to low shoot proliferation rates. Scanning electron microscopy (SEM) of the foliar surface showed that the stomatal density was highest in 10 μM MemTTHP-treated and lowest in 10 μM MemTR-treated plantlets. Prolonging the culture duration as well as increasing CK concentrations reduced the pigment content. However, the drastic breakdown in chlorophyll pigments beyond 50 days was slightly inhibited by the presence of mT, mTR, MemTTHP and BA compared to the control. Current findings indicate the potential anti-senescence activity of the topolins such as mT, mTR and MemTTHP under in vitro conditions. This study articulates that the right choice and concentration of CKs applied during in vitro propagation may alleviate photomixotrophic-induced physiological stress that usually accompanies the transfer of plantlets to ex vitro conditions. Findings indicate that the effect of subculturing contributed significantly to the higher rate of variation in 'Williams' bananas in vitro. The presence of CK in the culture media apparently aggravated the stress on the explants as indicated in the relatively higher percentage polymorphic bands compared to the controls. Among the tested CKs, the use of mTR and MemTTHP caused the least detrimental effect on the regenerants while mT-treated plantlets had the most polymorphic bands. Hence, it is recommended that subculturing cycles from the initial explant establishment should be limited to a maximum of five. The use of SW and KAR1 improved the level of photosynthetic pigment and phenolic compounds in the micropropagated bananas. However, they had a negative effect on shoot proliferation; hence their inclusion is more desired when used at the rooting phase of micropropagation. Perhaps, these compounds could be used in conjunction with auxin to increase the number of roots prior to the acclimatization stage. The enhanced photosynthetic pigment level resulting from addition of SW and KAR1 would also play a vital role during acclimatization of the micropropagated plants. The present finding serves as an alternative approach, available to researchers for improving the quantity of secondary metabolites in micropropagated plants. The highest regeneration rate (93%) was observed in BA + roscovitine treatment while mT + INCYDE-treated plantlets produced most shoots. Treatment with BA + roscovitine had the highest shoot length and biomass. Although not significant, there was more proanthocyanidins in BA + roscovitine treatments compared to the treatment with BA alone. On the contrary, total phenolics were significantly higher in mT + roscovitine treatment than in the mT-treated regenerants. The presence of roscovitine and/or INCYDE had no significant effect on the photosynthetic pigments of the banana plantlets. Forty-seven aromatic and isoprenoid CKs categorized into nine CK-types were detected at varying concentrations. The presence of mT + roscovitine and/or INCYDE increased the levels of O-glucosides, while 9-glucosides remained the major derivative in the presence of BA. Generally, the underground parts had higher CK levels than the aerial parts; however the presence of INCYDE increased the level of CK quantified in the aerial parts of both CK treated plantlets. Apparently, the presence of INCYDE serves to enhance transportation of the CK towards the aerial regions. From a practical perspective, the use of roscovitine and INCYDE in PTC could be crucial in the alleviation of commonly observed in vitro-induced physiological abnormalities. Soil drenching with SW significantly increased the root length (1:1000 and 1:500 dilutions) as well as fresh and dry weight (1:1000; 1:500 and 1:250 dilutions) when compared to foliar application. Vermicompost leachate (1:10 and 1:5 dilutions) significantly enhanced the shoot length, root length, leaf area and dry weights. Vermicompost leachate (1:20; 1:10 and 1:5 dilutions) also significantly increased the number of off-shoots. The positive effect on rooting is beneficial for acclimatization and establishment of tissue-cultured banana plantlets in nurseries and subsequent transfer to the field. However, field trials will be necessary to substantiate the effects demonstrated by these compounds. In an attempt to contribute to improving banana micropropagation, the current findings provide additional evidence on the increasing advantage of topolins over BA. Nevertheless, some detrimental physiological effects observed with some of the topolins (for example, MemT and MemTR) are clear indication that they should not be taken as a panacea in PTC. Besides optimizing efficient PTC protocols through stringent choice of CKs, other associated physiological and metabolic events taking place in culture during the optimization process need more in-depth investigation. In addition to contributing towards the better understanding of the mode of action of these CKs, such an approach will help solve associated physiological and developmental problems in vitro. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Atlikta istorinių kobalto pigmentų analogų Rentgeno spindulių difrakcinė analizė parodė, kad metodas efektyvus, nustatant kobalto šviesiai violetinį CoNH4PO4•H2O, kobalto mėlynąjį šviesų, ceruleumą ir kobalto žalsvai mėlyną CoO·ZnO, jų švino glazūrose, bet netinka aureolino [K3(Co(NO2)6]•3H2O, kobalto tamsiai violetinio Co3(PO4)2, kobalto mėlynojo tamsus, kobalto melsvai žalio ir smaltos CoO•nSiO2 nustatymui. IR spektroskopiniai tyrimai parodė, kad šis metodas efektyvus, kokybiškai nustatant neoksidinius kobalto pigmentus aureoliną, kobalto šviesiai violetinį, kobalto tamsiai violetinį jų švino glazūrose. Paprastu nusodinimo metodu susintetintas kobalto pigmentas violetinis šviesusis CoNH4PO4, pasižymintis analogiškomis fizikinėmis savybėmis, kaip ir komercinis Kremer Pigmente pigmentas. Sukurtas naujas, patogus ir pakankamai tikslus IR spektroskopinis SiO2 kiekio CoO ir SiO2 mišiniuose (ribose tarp 9,1-50 mol%) ir kobalto pigmente smaltoje CoO×nSiO2 (ribose tarp 20 iki 50 mol%) nustatymo metodas. Zolių-gelių metodu susintetinti ir visapusiškai ištirti nauji kobalto pigmentai: špinelio struktūros kobalto aliuminatas CoAl2O4 ir chromatas CoCr2O4 bei kobalto, aliuminio ir neodimio oksidų mišiniai (CoAl1,75Nd0,25O4, CoAl1,5Nd0,5O4, CoAlNdO4), pasižymintys spalvinėmis keraminių pigmentų savybėmis. Pirmą kartą zolių-gelių metodu susintetinti ir visapusiškai ištirti nauji kobalto pigmentai: vienfazis perovskito struktūros neodimio kobaltatas NdCoO3, mišrūs perovskitiniai neodimio... [toliau žr. visą tekstą] / X-ray diffraction analysis (XRD), infrared (IR) spectroscopy and scanning electron microscopy have been used for the characterization of cobalt-based pigments (Kremer Pigmente) and their lead-based glazes. It was also demonstrated that XRD analysis could be successfully used for the identification of cobalt pigments cobalt violet brilliant light CoNH4PO4•H2O, cobalt blue light, cerulean blue, cobalt green bluish CoO·ZnO in their glazes. However, only non-oxide cobalt pigments cobalt yellow [K3(Co(NO2)6]•3H2O, cobalt violet brilliant light and cobalt violet dark Co3(PO4)2 could be determined in their glazes using IR spectroscopy. The similarity of all SEM images of cobalt-based glazes let us to conclude, that the main morphological features of glazes are not dependent on the nature of cobalt pigment. The single phase cobalt violet light brilliant pigment has been synthesized using a simple co-precipitation approach. The characteristics of the obtained product were compared with those of a commercial sample purchased from Kremer Pigmente. For the first time to our knowledge, it was demonstrated that the characteristic Si-O absorption band at 812 cm-1 could be successfully used as indicator in the evaluation of molar ratio of CoO and SiO2 in their mixture. The novel method for the determination of SiO2 in physical mixtures of CoO ir SiO2 (in the range 9,1-50 %) or blue cobalt smalt pigment (CoO×nSiO2) (in the range 20-50 %) by FTIR spectroscopy is suggested. New cobalt-based... [to full text]

Cette thèse, financée par la Fondation des Sciences du Patrimoine, Patrima, a pour but la compréhension du mécanisme chimique responsable du brunissement de certains pigments verts à base de cuivre, sous forme de complexes organométalliques, utilisés en peinture de l'Antiquité à la Renaissance. Il s'agit du " vert de gris " et du " résinate de cuivre ". La variation chromatique de ces pigments engendre une perte de lisibilité de l'œuvre et pose un important problème de conservation. La détermination des réactions impliquées dans l'altération est fondamentale pour définir une méthodologie d'intervention. Afin de clarifier le mécanisme responsable du changement de couleur il est nécessaire d'étudier d'une part la géométrie du centre métallique et d'autre part la nature des liaisons cuivre-ligand. Dans ce but une stratégie multianalytique a été développée. Elle est basée sur la reconstitution des composés utilisés par les artistes et de ceux qui peuvent se former dans les couches picturales, et sur leur caractérisation, avant et après un vieillissement accéléré (thermique oupar exposition à la lumière). La synthèse des ces systèmes modèles a permis d'évaluer l'influence de plusieurs paramètres (solvant, pH, température et temps de réaction) sur la structure des complexes. Les produits de départ et les composés de dégradation ont été analysés par différentes techniques. L'étude des morphologies et la répartition chimique du cuivre au sein des systèmes est réalisée par MEB -EDS. La structure moléculaire a été caractérisée par IRTF diffraction des rayons X, spectroscopie d'absorption des rayons X et par résonance paramagnétique électronique. La caractérisation des produits de dégradation présents dans la phase organique est effectuée par chromatographie en phase gazeuse couplée à la spectrométrie de masse. En parallèle l'étude de leurs propriétés optiques a été réalisée par spectroscopie UV-visible. Les données collectées sont comparées à celles obtenues, par les mêmes méthodes analytiques, sur des échantillons de couches picturales prélevés sur des œuvres peintes plus ou moins altérées. Ce travail comparatif a permis à la fois de mieux comprendre les mécanismes de formation et de transformation au cours du vieillissement de ces systèmes hybrides organique-inorganique, d'évaluer quels paramètres ont plus d'influence sur l'altération et de valider ou d'invalider certaines hypothèses proposées concernant les changements des propriétés optiques observées.

There has been a considerable effort in the last years to decrease the amount of volatile organic compounds (VOCs) present in organic coatings. The risks to human health and environmental hazards associated with VOCs, governmental directives, and economic factors are the main driving forces behind this effort. One way of achieving less or no VOC containing coating systems is to produce low viscosity resins. Hyperbranched resins owing to their globular structure have low viscosities and are promising materials for decreasing the VOCs. In this research hyperbranched resins having properties close to alkyds were synthesized. Dipentaerythritol, which was used as the core was esterified with dimethylol propionic acid. The hyperbranched polyester was then esterified with the castor oil fatty acids (Castor FA). The hydroxyl group of the ricinoleic acid present in the castor FA was modified with different amounts of linseed oil fatty acids (Linseed FA) and benzoic acid. The chemical characterization of the resins was achieved by FTIR spectroscopy and the thermal properties were determined by DSC. Then, the physical and the mechanical tests were carried out. The resins containing the Castor FA only and 32.5 % Linseed FA in addition to the Castor FA had 24 and 68 Persoz hardness, respectively. The viscosity of the resins decreased from 17.3 Pa&amp / #61655 / s to 5.8 Pa&amp / #61655 / s as the amount of the Linseed FA was increased. The resins showed excellent adhesion, gloss, flexibility and formability.

In this research hyperbranched resins containing fatty acid residues like alkyds were synthesized. Dipentaerythritol which has six hydroxyl groups was used as the core molecule, and it was transesterified with (i) castor oil, and (ii) a mixture of castor oil and linseed oil at 240&deg / C in the presence of sodium hydroxide as catalyst. The resulting molecule, in either case, was then esterified with dimethylol propionic acid at 140&deg / C in the presence of p-toluene sulfonic acid as catalyst. Melamine-formaldehyde resin was synthesized to be used with the synthesized hyperbranched resins, and it was successfully modified by all hyperbranched resins at a ratio of 3:1. FTIR spectroscopy was used to characterize the hyperbranched resins and the thermal properties were determined by DSC. DSC showed that the hyperbranched resins decomposed between 315-345&deg / C. The viscosity of the resin that was synthesized by using only castor oil was 3.0 Pa.s and by using 50% linseed oil it was 1.0 Pa.s. When reacted with dimethylol propionic acid, the former&rsquo / s viscosity increased to 7.0 Pa.s, and the second&rsquo / s viscosity increased to 3.7 Pa.s. The hyperbranched resins showed excellent adhesion, gloss, flexibility, and formability. The mixture of hyperbranched resin plus melamine-formaldehyde resin samples had higher hardness values but lower gloss, adhesion and bending resistance values than the hyperbranched resins, and they had good impact and abrasion resistances.

L'objectiu primordial d'aquest treball és la caracterització i l'estudi de materials i la interpretació del color en la pintura de retaules d'època gòtica.Per aquest estudi s'ha desenvolupat una metodologia en la caracterització dels materials, s'ha creat una base de dades de resultats analítics i de cromaticitat de substàncies de referència i, posteriorment s'han aplicat aquestes tècniques a una selecció d'obres del pintor Jaume Huguet (s.XV).Ha estat necessària la utilització de tècniques instrumentals diverses i metodologies de tractament de les mostres específiques. Les tècniques instrumentals utilitzades han estat: microscòpia óptica, l'espectrofotometria visible de reflectància difusa, la difracció de raigs X, l'espectroscòpia i microespectroscòpia FTIR, la microscòpia electrònica de rastreig amb un detector d'energies dispersades acoblat SEM-EDS, i l'espectroscòpia Raman. La relació de pigments caracteritzats correspon a: PbCO3/2PbCO3Pb(OH)2 (blanc de plom), 2CuCO3·Cu(OH)2 (atzurita), HgS (estructura de cinabri), 2PbOSnO2 (pigment groc de plom i estany (tipus I), pigment verd de coure associat a una diversitat de compostos, Cu2Cl(OH)3 (atacamita, paratacamita,...), acetats i carbonats de coure, pigments terra (òxids de ferro), carbó amorf (negre de carbó de diferent procedències), pigment laca vermell (es suggereix àcid carmínic), a més de les làmines de metall d'or i de plata. L'aglutinant utilitzat en major extensió és el rovell d'ou o bé la barreja de rovell i clara d'ou. Això no obstant, s'ha trobat la utilització d'altres aglutinants (cola animal, oli assecant, clara d'ou) per a determinats pigments. Les mesures dels gruixos de les làmines de metall i l'estudi del model de color demostren que la preparació vermella aplicada (bol) sota aquestes làmines, no afecte el cromatisme del metall. S'estudien els aspectes de conservació i evolució que els materials han sofert amb el temps, algunes alteracions són comunes a les diferents peces. A partir de les mesures de color es proposa un model de color que disminueix l'efecte d'engroguiment que presenten les obres estudiades com a conseqüència de l'envelliment dels materials orgànics presents.

Syngnathidae (seahorse, pipefish, pipehorses & seadragons) are highly visual feeders with different species feeding on specific types of prey, a behaviour that has been related to snout length. Worldwide, many species have become threatened by habitat destruction, collection for the aquarium trade and exploitation for traditional medicine, as well as recreational and commercial bycatch. Attempts to establish aquaculture programs have been of limited success. Little is known about their visual capabilities in detail. The visual systems of fishes are known to have evolved specific adaptations that can be related to the colour of water in which they live and specific visual tasks such as predator detection and acquisition of food. This study examined the ocular and retinal morphology, photoreceptor structure and spectral sensitivity of adult individuals of a local pipefish (S. argus), local seahorse (Hippocampus subelongatus) which both inhabit green water seagrass beds, and a tropical species of seahorse (Hippocampus barbouri) from blue water coral reefs. Some juveniles were also investigated. Accordingly, we developed an understanding of the features that are common to all syngnathids and those that have evolved for specific environments. Cryosections of the eyes were taken to determine morphological distinctions of this group. Lens characteristics measured using a spectrophotometer determined 50% cut-off wavelengths below 408nm for all 3 species, hence no transmission of UV light to the retina. Histological examination determined a cone dominated fovea in the ventro-temporal retina and very large rods concentrated in the peripheral retina and adjacent to the optic nerve. Microspectrophotometry measured the absorption characteristics of the visual pigments within the photoreceptors showing the presence and maximum sensitivity (λmax) of rods, SWS single cones, and a broad, complex array of LWS double/twin cones. The results are discussed in relation to the light environment inhabited by each species and their feeding requirements. The implications for the design of suitable light environments for aquarium and aquaculture programs for the Syngnathidae are also discussed. Rearing success of this family of fish, for both the aquarium trade and re-stocking programs, would be advised to take lighting regimes and specifics of the animals’ vision into account