http://hdl.handle.net/2117/3796 Wed, 19 Jun 2013 14:25:31 GMT 2013-06-19T14:25:31Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/17584 Title: Determination of fungicides in residual tanning floats using solid phase micro extraction Authors: Font Vallès, Joaquim; Reyes Reyes, Maria; Cuadros, Sara; Bacardit Dalmases, Anna; Ollé Otero, Lluís; Marsal Monge, Agustín Abstract: Solid-phase microextraction (SPME) was optimized for extraction of the leather preservative agents 2-(thiocyanomethylthio)-benzothiazole (TCMTB), 4-chloro-3-methylphenol (PCMC), 2-phenylphenol (OPP), 2-Octyl-3(2H)-isothiazolone (OIT), 2-mercaptobenzothiazol (MBT) and 3-iodo-2-propynyl-butylcarbamate (IPBC) in spent tanning floats. Determination was carried out by high performance liquid chromatography (HPLC) with photo diode array detection (PDA). The following parameters were studied to achieve the maximum efficiency in extraction: fiber type, adsorption conditions (extraction time, ionic strength, temperature) and desorption parameters (time, temperature and composition of the desorption solvent). Results indicate that SPME using a 60um polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber is appropriate for the extraction of these types of compounds. Recoveries ranged from 82% to 116% with RSDs between +-8% and +-12% and limits of detection below 1 mg/L except for IPBC. The optimized procedure was successfully applied for the determination of leather preservatives in eleven residual tanning floats taken from different companies. This method enables us to determine quantitatively the fungicides contained in th residual floats. Consequently, it will constitute a very useful tool to improve the preservative uptake in leather manufacturing processes Tue, 05 Feb 2013 15:48:08 GMT http://hdl.handle.net/2117/17584 2013-02-05T15:48:08Z Font Vallès, Joaquim; Reyes Reyes, Maria; Cuadros, Sara; Bacardit Dalmases, Anna; Ollé Otero, Lluís; Marsal Monge, Agustín no Solid-phase microextraction (SPME) was optimized for extraction of the leather preservative agents 2-(thiocyanomethylthio)-benzothiazole (TCMTB), 4-chloro-3-methylphenol (PCMC), 2-phenylphenol (OPP), 2-Octyl-3(2H)-isothiazolone (OIT), 2-mercaptobenzothiazol (MBT) and 3-iodo-2-propynyl-butylcarbamate (IPBC) in spent tanning floats. Determination was carried out by high performance liquid chromatography (HPLC) with photo diode array detection (PDA). The following parameters were studied to achieve the maximum efficiency in extraction: fiber type, adsorption conditions (extraction time, ionic strength, temperature) and desorption parameters (time, temperature and composition of the desorption solvent). Results indicate that SPME using a 60um polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber is appropriate for the extraction of these types of compounds. Recoveries ranged from 82% to 116% with RSDs between +-8% and +-12% and limits of detection below 1 mg/L except for IPBC. The optimized procedure was successfully applied for the determination of leather preservatives in eleven residual tanning floats taken from different companies. This method enables us to determine quantitatively the fungicides contained in th residual floats. Consequently, it will constitute a very useful tool to improve the preservative uptake in leather manufacturing processes http://hdl.handle.net/2117/16482 Title: Evaluation of a lime-mediated sewage sludge stabilisation process. Product characterisation and technological validation for its use in the cement industry Authors: Flores, J.; Larrotcha, E.; Fos, C.; Husillos Rodríguez, N.; Granados, R.J.; Blanco Varela, M.Teresa; Cortina Pallás, José Luís; Martínez Ramírez, Sagrario; Marsal Astort, Montserrat; Guillem, Manel; Puig, J. Abstract: This paper describes an industrial process for stabilising sewage sludge (SS) with lime and evaluates the viability of the stabilised product, denominated Neutral, as a raw material for the cement industry. Lime not only stabilised the sludge, raised the temperature of the mix to 80–100 C, furthering water evaporation, portlandite formation and the partial oxidation of the organic matter present in the sludge. Process mass and energy balances were determined. Neutral, a white powder consisting of portlandite (49.8%), calcite (16.6%), inorganic oxides (13.4%) and organic matter and moisture (20.2%), proved to be technologically apt for inclusion as a component in cement raw mixes. In this study, it was used instead of limestone in raw mixes clinkerised at 1400, 1450 and 1500 C. These raw meals exhibited greater reactivity at high temperatures than the limestone product and their calcination at 1500 C yielded clinker containing over 75% calcium silicates, the key phases in Portland clinker. Finally, the two types of raw meal (Neutral and limestone) were observed to exhibit similar mineralogy and crystal size and distribution. Fri, 14 Sep 2012 08:09:11 GMT http://hdl.handle.net/2117/16482 2012-09-14T08:09:11Z Flores, J.; Larrotcha, E.; Fos, C.; Husillos Rodríguez, N.; Granados, R.J.; Blanco Varela, M.Teresa; Cortina Pallás, José Luís; Martínez Ramírez, Sagrario; Marsal Astort, Montserrat; Guillem, Manel; Puig, J. no Alximix, Cement reuse, Clinker, Lime stabilisation, Neutral, Sewage sludge This paper describes an industrial process for stabilising sewage sludge (SS) with lime and evaluates the viability of the stabilised product, denominated Neutral, as a raw material for the cement industry. Lime not only stabilised the sludge, raised the temperature of the mix to 80–100 C, furthering water evaporation, portlandite formation and the partial oxidation of the organic matter present in the sludge. Process mass and energy balances were determined. Neutral, a white powder consisting of portlandite (49.8%), calcite (16.6%), inorganic oxides (13.4%) and organic matter and moisture (20.2%), proved to be technologically apt for inclusion as a component in cement raw mixes. In this study, it was used instead of limestone in raw mixes clinkerised at 1400, 1450 and 1500 C. These raw meals exhibited greater reactivity at high temperatures than the limestone product and their calcination at 1500 C yielded clinker containing over 75% calcium silicates, the key phases in Portland clinker. Finally, the two types of raw meal (Neutral and limestone) were observed to exhibit similar mineralogy and crystal size and distribution. http://hdl.handle.net/2117/16414 Title: SR-XRD and SR-FTIR study of the alteration of silver foils in medieval paintings Authors: Salvadó Cabré, Nativitat; Buti Papiol, Salvador; Labrador, A.; Cinque, Gianfelice; Emerich, Hermann; Pradell Cara, Trinitat Abstract: Altarpieces and polychrome carved wood from the fifteenth century AD usually exhibit golden and silvery areas by the application of a very thin foil of metal. The metal foils were normally protected from the atmosphere by a varnish or resin which maybe either preserved or absent. Moreover, they were glued to the background surface by adhesive substances (egg yolk, drying oil or animal glue). The high proportion of the glueing substances often renders the development of reaction compounds. With time, silver alters blacken or simply disappear completely. In this paper, we study the alterations to metal foils from a selection of fifteenth century artworks showing different glueing agents, organic coatings and several degrees of conservation of the organic coatings and metal leafs. The submillimetric layered structure and the high variability and low amount of most of the compounds present in the different layers, as well as their differing nature (organic and inorganic) make the use of micron-sensitive highresolution techniques essential for their study. In particular, the high resolution, high brilliance and small footprint renders synchrotron radiation most adequate for their study. SR-XRD was performed to identify the reaction compounds formed in the different layers; μFTIR was used at to identify the silver protecting organic coatings, the metal foil glueing layers and the corresponding reaction compounds. The results obtained suggest that atmospheric corrosion is the dominant mechanism, and therefore that the degree of corrosion of the metal foils is mainly related to the conservation state of the protecting coatings. Mon, 03 Sep 2012 08:12:52 GMT http://hdl.handle.net/2117/16414 2012-09-03T08:12:52Z Salvadó Cabré, Nativitat; Buti Papiol, Salvador; Labrador, A.; Cinque, Gianfelice; Emerich, Hermann; Pradell Cara, Trinitat no Altarpieces and polychrome carved wood from the fifteenth century AD usually exhibit golden and silvery areas by the application of a very thin foil of metal. The metal foils were normally protected from the atmosphere by a varnish or resin which maybe either preserved or absent. Moreover, they were glued to the background surface by adhesive substances (egg yolk, drying oil or animal glue). The high proportion of the glueing substances often renders the development of reaction compounds. With time, silver alters blacken or simply disappear completely. In this paper, we study the alterations to metal foils from a selection of fifteenth century artworks showing different glueing agents, organic coatings and several degrees of conservation of the organic coatings and metal leafs. The submillimetric layered structure and the high variability and low amount of most of the compounds present in the different layers, as well as their differing nature (organic and inorganic) make the use of micron-sensitive highresolution techniques essential for their study. In particular, the high resolution, high brilliance and small footprint renders synchrotron radiation most adequate for their study. SR-XRD was performed to identify the reaction compounds formed in the different layers; μFTIR was used at to identify the silver protecting organic coatings, the metal foil glueing layers and the corresponding reaction compounds. The results obtained suggest that atmospheric corrosion is the dominant mechanism, and therefore that the degree of corrosion of the metal foils is mainly related to the conservation state of the protecting coatings. http://hdl.handle.net/2117/15982 Title: Study of the effect of temperature, relative humidity and UV radiation on chrome-tanned leather ageing Authors: Bacardit Dalmases, Anna; Jorba, Montse; Font Vallès, Joaquim; Ollé Otero, Lluís Abstract: Since leather is strongly affected by three main environmental parameters: temperature, relative humidity and UV radiation, this piece of research focuses on the effect that these three factors have on chrome-tanned leather ageing. Chrome tanned leathers were exposed to weathering effects in a climatic chamber in order to identify the most important variables affecting this weathering process and also to check for any possible interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) were used as statistical tools for estimating the effects of the parameters Thu, 07 Jun 2012 15:37:22 GMT http://hdl.handle.net/2117/15982 2012-06-07T15:37:22Z Bacardit Dalmases, Anna; Jorba, Montse; Font Vallès, Joaquim; Ollé Otero, Lluís no Since leather is strongly affected by three main environmental parameters: temperature, relative humidity and UV radiation, this piece of research focuses on the effect that these three factors have on chrome-tanned leather ageing. Chrome tanned leathers were exposed to weathering effects in a climatic chamber in order to identify the most important variables affecting this weathering process and also to check for any possible interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) were used as statistical tools for estimating the effects of the parameters http://hdl.handle.net/2117/15267 Title: Comparison of weathering variables on chrome-tanned and wet-white leather ageing Authors: Ollé Otero, Lluís; Jorba, Montse; Castell, Joan Carles; Font Vallès, Joaquim; Bacardit Dalmases, Anna Abstract: Leather is a natural material that can be used in different environments and often under aggressive environmental conditions that may cause premature ageing. The most important factors influencing the degradation of leather are temperature, relative humidity and UV radiation. Leathers with chrome tannage and wet-white leathers were exposed to weathering effects using a climatic chamber in order to identify the most important variables affecting this weathering process and to check for interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) have been employed as statistical tools for estimating the effects of the parameters Tue, 21 Feb 2012 10:39:49 GMT http://hdl.handle.net/2117/15267 2012-02-21T10:39:49Z Ollé Otero, Lluís; Jorba, Montse; Castell, Joan Carles; Font Vallès, Joaquim; Bacardit Dalmases, Anna no Leather is a natural material that can be used in different environments and often under aggressive environmental conditions that may cause premature ageing. The most important factors influencing the degradation of leather are temperature, relative humidity and UV radiation. Leathers with chrome tannage and wet-white leathers were exposed to weathering effects using a climatic chamber in order to identify the most important variables affecting this weathering process and to check for interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) have been employed as statistical tools for estimating the effects of the parameters http://hdl.handle.net/2117/13832 Title: Recovery of organic nitrogen from beamhouse wastewater in a hair recovery process Authors: Rius Carrasco, Antoni; Marsal Monge, Agustín; Bautista, E.; Cuadros, Sara; Reyes Reyes, Maria; Font Vallès, Joaquim Abstract: In the leather industry, in addition to the extrinsic contamination attributable to chemical products not absorbed by the hides, there is intrinsic contamination produced by the hides themselves. From each 100kg of raw material, 15kg of solubilised protein will end up in wastewater in the early stages of the process of transforming hides into leather. These proteins contain nearly 18% of nitrogen. In this study it is proposed to recover organic nitrogen from the proteins present in the effluents of the beamhouse operations of hides and the subsequent revalorization of the protein fraction obtained. This work seeks to characterize (the chemical oxygen demand (COD), total nitrogen, ammonium nitrogen, total soluble nitrogen, particulate nitrogen, organic nitrogen and protein) the wastewaters, individually or in groups, of the various beamhouse operations (soaking, unhairing-liming, washing, conditioning, deliming, bating, washing and pickling) with hair recovery. The studies are presented of the determination of the pH value (adjusted by means of buffers of acetic acid/sodium acetate) at which the greatest precipitate of the protein fraction is produced. In addition, the following tests were performed to characterize these precipitates: determination of the quantitative composition of the main components of the protein fraction (humidity, proteins, free amino acids, fats and other matter soluble in dichloromethane and ash); heavy metals content, calcium, magnesium, potassium and sodium and the composition in total amino acids with prior acid hydrolysis of the protein fraction with 6N hydrochloric acid. Wed, 09 Nov 2011 11:52:49 GMT http://hdl.handle.net/2117/13832 2011-11-09T11:52:49Z Rius Carrasco, Antoni; Marsal Monge, Agustín; Bautista, E.; Cuadros, Sara; Reyes Reyes, Maria; Font Vallès, Joaquim no In the leather industry, in addition to the extrinsic contamination attributable to chemical products not absorbed by the hides, there is intrinsic contamination produced by the hides themselves. From each 100kg of raw material, 15kg of solubilised protein will end up in wastewater in the early stages of the process of transforming hides into leather. These proteins contain nearly 18% of nitrogen. In this study it is proposed to recover organic nitrogen from the proteins present in the effluents of the beamhouse operations of hides and the subsequent revalorization of the protein fraction obtained. This work seeks to characterize (the chemical oxygen demand (COD), total nitrogen, ammonium nitrogen, total soluble nitrogen, particulate nitrogen, organic nitrogen and protein) the wastewaters, individually or in groups, of the various beamhouse operations (soaking, unhairing-liming, washing, conditioning, deliming, bating, washing and pickling) with hair recovery. The studies are presented of the determination of the pH value (adjusted by means of buffers of acetic acid/sodium acetate) at which the greatest precipitate of the protein fraction is produced. In addition, the following tests were performed to characterize these precipitates: determination of the quantitative composition of the main components of the protein fraction (humidity, proteins, free amino acids, fats and other matter soluble in dichloromethane and ash); heavy metals content, calcium, magnesium, potassium and sodium and the composition in total amino acids with prior acid hydrolysis of the protein fraction with 6N hydrochloric acid. http://hdl.handle.net/2117/13670 Title: Inter-laboratory study on formaldehyde determination by HPLC Authors: Marsal Monge, Agustín; Font Vallès, Joaquim; Viera, Susanna; Cuadros, Sara; Rius Carrasco, Antoni; Reyes Reyes, Maria; Verdú, Emilio; Jorba, Montse; Juárez, Miguel-Angel Abstract: The colorimetric determination of formaldehyde in a water extract of a leather sample is a procedure that has been criticized because of possible interferences of other aldehydes and coloured substances that could interfere in the spectrophotometric detection. The measurement by liquid chromatography HPLC is an alternative method that was developed some years ago. This method is more sophisticated but more selective and free of the aforementioned interferences. It is not sensitive to coloured extracts. With the implementation of HPLC equipment in many laboratories, this choice has become feasible in our sector. The process is selective. Formaldehyde is separated and quantified as a derivative from other aldehydes and ketones by liquid chromatography. The free-formaldehyde and formaldehyde which is hydrolysed during extraction to yield free-formaldehyde are detected by this method. The sample is eluted with water at 40ºC. The eluate is mixed with 2,4 dinitrophenylhydrazine, whereby aldehydes and ketones react to yield the respective hydrazones. These are separated by means of a reversed-phase HPLC method, detected at 350 nm and quantified. The aim of this work is to present a collaborative inter-laboratory study coordinated by the Igualada Leather Technology School and carried out with four other laboratories that had previosly implemented the HPLC method or that were planning to do this. Determination of formaldehyde content in leather was carried out in each laboratory in accordance with prEN ISO 17226:2005 - HPLC Standard, developed by the Committee CEN/TC 289. Part 2 of the ISO 5725 Standard (Basic method for the determination of repeatability and reproducibiliry of a standard measurement method) was applied to examine the results. The study proved successful. The HPLC method achieved very reproducible results between laboratories. This work has also demonstrated that other aldehydes, glutaraldehyde included, do not interfere in the chromatographic method. The use of a PDA detector increases the confidence of the detection of formaldehyde in leather samples Wed, 26 Oct 2011 14:45:06 GMT http://hdl.handle.net/2117/13670 2011-10-26T14:45:06Z Marsal Monge, Agustín; Font Vallès, Joaquim; Viera, Susanna; Cuadros, Sara; Rius Carrasco, Antoni; Reyes Reyes, Maria; Verdú, Emilio; Jorba, Montse; Juárez, Miguel-Angel no The colorimetric determination of formaldehyde in a water extract of a leather sample is a procedure that has been criticized because of possible interferences of other aldehydes and coloured substances that could interfere in the spectrophotometric detection. The measurement by liquid chromatography HPLC is an alternative method that was developed some years ago. This method is more sophisticated but more selective and free of the aforementioned interferences. It is not sensitive to coloured extracts. With the implementation of HPLC equipment in many laboratories, this choice has become feasible in our sector. The process is selective. Formaldehyde is separated and quantified as a derivative from other aldehydes and ketones by liquid chromatography. The free-formaldehyde and formaldehyde which is hydrolysed during extraction to yield free-formaldehyde are detected by this method. The sample is eluted with water at 40ºC. The eluate is mixed with 2,4 dinitrophenylhydrazine, whereby aldehydes and ketones react to yield the respective hydrazones. These are separated by means of a reversed-phase HPLC method, detected at 350 nm and quantified. The aim of this work is to present a collaborative inter-laboratory study coordinated by the Igualada Leather Technology School and carried out with four other laboratories that had previosly implemented the HPLC method or that were planning to do this. Determination of formaldehyde content in leather was carried out in each laboratory in accordance with prEN ISO 17226:2005 - HPLC Standard, developed by the Committee CEN/TC 289. Part 2 of the ISO 5725 Standard (Basic method for the determination of repeatability and reproducibiliry of a standard measurement method) was applied to examine the results. The study proved successful. The HPLC method achieved very reproducible results between laboratories. This work has also demonstrated that other aldehydes, glutaraldehyde included, do not interfere in the chromatographic method. The use of a PDA detector increases the confidence of the detection of formaldehyde in leather samples http://hdl.handle.net/2117/13641 Title: Auxiliary agents with non-swelling capacity used in pickling/tanning processes. Part 3. Authors: Marsal Monge, Agustín; Ramón, Palop; Font Vallès, Joaquim; Cot Cosp, Jaume; Frías, Vicente; Manich Bou, Albert M. Abstract: In the present work, the behaviour of the four commercial products with non-swelling capacity in the pickling/tanning processes of sheepskins is studied. The successful application of these products to thinner skins would allow us to reduce salinity and, hence, the conductivity of waste waters. The results obtained by using these products are compared with those achieved by applying a conventional pickling/tanning process. Mon, 24 Oct 2011 09:37:15 GMT http://hdl.handle.net/2117/13641 2011-10-24T09:37:15Z Marsal Monge, Agustín; Ramón, Palop; Font Vallès, Joaquim; Cot Cosp, Jaume; Frías, Vicente; Manich Bou, Albert M. no In the present work, the behaviour of the four commercial products with non-swelling capacity in the pickling/tanning processes of sheepskins is studied. The successful application of these products to thinner skins would allow us to reduce salinity and, hence, the conductivity of waste waters. The results obtained by using these products are compared with those achieved by applying a conventional pickling/tanning process. http://hdl.handle.net/2117/13605 Title: Environmental optimization of chromium recovery from tannery sludge using a life cycle assessment approach Authors: Kiliç, Eylem; Puig Vidal, Rita; Baquero Armans, Grau; Font Vallès, Joaquim; Colak, Selime; Gürler, Deniz Abstract: Life cycle assessment (LCA) was used to evaluate the environmental impact of an oxidative chromium recovery method from tannery sludge, in comparison with the usual landfilling process. Three improvement options (water reduction, byproduct use and anaerobic sludge digestion) were considered. The results showed that the proposed chromium recovery process would be better environmentally than conventional landfilling in all the evaluated impact categories if the amount of chromium recovered was 43 kg per ton of sludge. This amount could be recovered if the chromium concentration was about 20 times higher than that considered in this study. Alternatively, a lower chromium concentration would produce a better result if the recovery method was optimized and implemented at industrial rather than laboratory scale, and if more accurate data were provided on environmental credits for avoiding the chromium production process. Thus, the recovery method is environmentally beneficial when tannery sludge contains a chromium concentration of about 100,000 ppm. According to the literature, such concentrations are not unusual. The results could serve as the basis for further environmental improvements in chromium recovery and tannery sludge management and should be used in decision-making processes, especially for end-of-pipe treatments. Thu, 20 Oct 2011 15:56:58 GMT http://hdl.handle.net/2117/13605 2011-10-20T15:56:58Z Kiliç, Eylem; Puig Vidal, Rita; Baquero Armans, Grau; Font Vallès, Joaquim; Colak, Selime; Gürler, Deniz no Life cycle assessment (LCA) was used to evaluate the environmental impact of an oxidative chromium recovery method from tannery sludge, in comparison with the usual landfilling process. Three improvement options (water reduction, byproduct use and anaerobic sludge digestion) were considered. The results showed that the proposed chromium recovery process would be better environmentally than conventional landfilling in all the evaluated impact categories if the amount of chromium recovered was 43 kg per ton of sludge. This amount could be recovered if the chromium concentration was about 20 times higher than that considered in this study. Alternatively, a lower chromium concentration would produce a better result if the recovery method was optimized and implemented at industrial rather than laboratory scale, and if more accurate data were provided on environmental credits for avoiding the chromium production process. Thus, the recovery method is environmentally beneficial when tannery sludge contains a chromium concentration of about 100,000 ppm. According to the literature, such concentrations are not unusual. The results could serve as the basis for further environmental improvements in chromium recovery and tannery sludge management and should be used in decision-making processes, especially for end-of-pipe treatments. http://hdl.handle.net/2117/12817 Title: Salinity reduction in the production of nappa skins by using agents with non-swelling capacity in pickling/tanning Authors: Marsal Monge, Agustín; Rius Carrasco, Antoni; Cot Cosp, Jaume; Lalueza Baro, Joana; Ramón, Palop; Font Vallès, Joaquim Thu, 23 Jun 2011 10:06:37 GMT http://hdl.handle.net/2117/12817 2011-06-23T10:06:37Z Marsal Monge, Agustín; Rius Carrasco, Antoni; Cot Cosp, Jaume; Lalueza Baro, Joana; Ramón, Palop; Font Vallès, Joaquim no http://hdl.handle.net/2117/12813 Title: Comparisonof the effect of the tropical test on both chrome-tanned and wet-white upholstery leather Authors: Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Bacardit Dalmases, Anna Abstract: Automotive upholstery leather can undergo extreme environmental conditions that may cause premature ageing. Leather is strongly affected by three main environmental parameters: temperature,relative humidity and UV radiation. UV radiation causes colour change, fading, surface erosion, loss of gloss, etc. Increasing the levels of UV radiation represents a primary accelerating factor for leather ageing. Temperature produces thermal oxidation degradations, subsequent reaction rates and acceleration of other weathering reactions. Relative humidity acts as a chemical reagent in many hydrolytic weathering reactions and as a physical stressor of leather. Additionally, when relative humidity is over 65% leather is susceptible to mould attack. The aim of this work is to compare the effect of the tropical environment exposure on both chrometanned and wet-white upholstery leather. Wed, 22 Jun 2011 11:49:21 GMT http://hdl.handle.net/2117/12813 2011-06-22T11:49:21Z Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Bacardit Dalmases, Anna no Automotive upholstery leather can undergo extreme environmental conditions that may cause premature ageing. Leather is strongly affected by three main environmental parameters: temperature,relative humidity and UV radiation. UV radiation causes colour change, fading, surface erosion, loss of gloss, etc. Increasing the levels of UV radiation represents a primary accelerating factor for leather ageing. Temperature produces thermal oxidation degradations, subsequent reaction rates and acceleration of other weathering reactions. Relative humidity acts as a chemical reagent in many hydrolytic weathering reactions and as a physical stressor of leather. Additionally, when relative humidity is over 65% leather is susceptible to mould attack. The aim of this work is to compare the effect of the tropical environment exposure on both chrometanned and wet-white upholstery leather. http://hdl.handle.net/2117/12812 Title: Biodegradation of wet-white leather Authors: Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna Abstract: This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier. Wed, 22 Jun 2011 11:31:03 GMT http://hdl.handle.net/2117/12812 2011-06-22T11:31:03Z Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna no This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier. http://hdl.handle.net/2117/11718 Title: The role of microspectroscopy techniques in the study of historic artworks Authors: Salvadó Cabré, Nativitat; Buti Papiol, Salvador; Pradell Cara, Trinitat Tue, 08 Mar 2011 15:10:13 GMT http://hdl.handle.net/2117/11718 2011-03-08T15:10:13Z Salvadó Cabré, Nativitat; Buti Papiol, Salvador; Pradell Cara, Trinitat no Infrared, Raman, Imaging, Microscopy http://hdl.handle.net/2117/10223 Title: Identification of reaction compounds in micrometric layers from gothic paintings using combined SR-XRD and SR-FTIR Authors: Salvadó Cabré, Nativitat; Buti Papiol, Salvador; Nicholson, J; Emerich, H; Labrador, A; Pradell Cara, Trinitat Abstract: Synchrotron radiation X-ray diffraction ( -SR-XRD) and Fourier transform infrared spectroscopy ( -SRFTIR) are used in the non-destructive identification of reaction and aging compounds from micrometric ancient painting layers. The combination of the micrometer size and non-destructive nature of the techniques together with the high resolution and brilliance of the synchrotron radiation has proved to be a procedure most advantageous for the study of reaction, aging and degradation processes. Copper, lead and calcium carboxylates and oxalates are determined in the chromatic, preparation and alteration layers from 15th century egg tempera and oil paintings. Their nature and crystallinity have been assessed. Some hypothesis about the mechanisms of development of both carboxylates and oxalates are presented. Tue, 09 Nov 2010 16:30:38 GMT http://hdl.handle.net/2117/10223 2010-11-09T16:30:38Z Salvadó Cabré, Nativitat; Buti Papiol, Salvador; Nicholson, J; Emerich, H; Labrador, A; Pradell Cara, Trinitat no Synchrotron radiation, XRD, FTIR, Metal carboxylates, Oxalates, Gothic paintings, Artwork Synchrotron radiation X-ray diffraction ( -SR-XRD) and Fourier transform infrared spectroscopy ( -SRFTIR) are used in the non-destructive identification of reaction and aging compounds from micrometric ancient painting layers. The combination of the micrometer size and non-destructive nature of the techniques together with the high resolution and brilliance of the synchrotron radiation has proved to be a procedure most advantageous for the study of reaction, aging and degradation processes. Copper, lead and calcium carboxylates and oxalates are determined in the chromatic, preparation and alteration layers from 15th century egg tempera and oil paintings. Their nature and crystallinity have been assessed. Some hypothesis about the mechanisms of development of both carboxylates and oxalates are presented. http://hdl.handle.net/2117/6592 Title: Sequential injection analysis with second-order treatment for the determination of dyes in the exhaustion process of tanning effluents Authors: Gómez, Verónica; Font Vallès, Joaquim; Callao, Maria Pilar Abstract: A sequential injection (SI)-DAD spectrophotometric method to control the exhaustion of dyes in a mixture of three dyes from a tanning industry process has been developed. It is based on an interdiffusion process of the sample and reagents which leads to a gradual fall in pH through the channel to the detector recording a data matrix. The aim of this paper is to develop a second-order calibration model that is unaffected by interferents by applying multivariate curve resolution with alternating least squares (MCR-ALS). We obtained a linear calibration in the 5–30 mg l−1 range with a correlation coefficient of 0.999 for each dye with detection limits of 2.6, 3.9 and 2.1 mg l−1 for Acid Red, Acid Brown and Acid Orange, respectively. The simultaneous determination of the three dyes from tanning samples showed a satisfactory precision for the three analytes. The method has been validated comparing the concentration of some spiked samples with the expected concentration using a t-paired test. When we used this method to study the exhaustion of dyes, we found that there were several stages in this process. These data may be the key to optimising the exhaustion process. Tue, 09 Mar 2010 17:09:01 GMT http://hdl.handle.net/2117/6592 2010-03-09T17:09:01Z Gómez, Verónica; Font Vallès, Joaquim; Callao, Maria Pilar no A sequential injection (SI)-DAD spectrophotometric method to control the exhaustion of dyes in a mixture of three dyes from a tanning industry process has been developed. It is based on an interdiffusion process of the sample and reagents which leads to a gradual fall in pH through the channel to the detector recording a data matrix. The aim of this paper is to develop a second-order calibration model that is unaffected by interferents by applying multivariate curve resolution with alternating least squares (MCR-ALS). We obtained a linear calibration in the 5–30 mg l−1 range with a correlation coefficient of 0.999 for each dye with detection limits of 2.6, 3.9 and 2.1 mg l−1 for Acid Red, Acid Brown and Acid Orange, respectively. The simultaneous determination of the three dyes from tanning samples showed a satisfactory precision for the three analytes. The method has been validated comparing the concentration of some spiked samples with the expected concentration using a t-paired test. When we used this method to study the exhaustion of dyes, we found that there were several stages in this process. These data may be the key to optimising the exhaustion process.