cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6857963.v1
title: Analysis of biodeterioration wood estate: use different techniques to obtain images

description: ABSTRACT This study was based on the current status of locomotive turntable of Provincial Railway Station in La Plata. It was inaugurated in 1910 and it was declared as architectural heritage in 2006. The locomotive turntable is 200 meters from this station and it is a structure that consists in wooden slats of Schinopsis sp. into metal framework. Currently, this structure shows an advanced status of degradation caused by environmental and biological factors. The objective of this work was to determine the wood fungal degradation by non-destructive methods: area occupied by fungus (mycelium and basidiomata) were observed by X-ray radiography (XR) and Computer tomography (TC) and quantified by image analysis with ImageJ software. To establish the microstructural degradation (cell wall), ultrathin cut were analyzed by scanning electron microscopy (SEM). The radiographic images were analyzed by ImageJ and allowed to determinate that the affected area by wood decay fungus inside wood was higher than outside (superficial view). This confirms that external degradation did not correlate with the internal status. TC images showed internal wood structure loss, which were correlated with the presence of fungal hyphae along the entire slat. Finally, wood microstructure was analyzed by SEM, in these images could be observed the advanced deterioration status of the wood structure, where there are high fungal colonization (hyphae) and wood microstructure loss (the cell wall was degraded). This deterioration analysis allows an indirect measurement of the structural condition of the material without destroying it. It was concluded that degradation analysis by images is a non-destructive alternative, and validated methodology to determine material status. This is essential in heritage conservation because it allows defining correctly the degradation status that is useful to planning a conservation strategy, avoiding the asset loss.
DOI: 10.6084/m9.figshare.6857966.v1
title: Characterization of epoxy resins for use in end fittings of flexible pipes

description: ABSTRACT In the offshore productions of gas and oil are frequently used flexible pipes. The end fitting is the connection between the flexible pipe body and the production unit, at the assembly of this component is used epoxy resin to fill the free space inside it. This polymeric material holds the tensile armor wires to form the anchoring system. A critical point in the oil industry advance, beyond the technological frontier of offshore oil extraction, is the structural performance of the end fittings. In this critical component, the epoxy material must have the appropriate characteristics that allow resist the mechanical solicitations. This paper presents a characterization of five epoxy materials with the intention to determine their ability to be applied at end fittings. Pull out tests, compression tests, shear testes and measurement of hardness, were made to value the performance of those materials for this application. The performance of the five resins was compared through a TOPSIS analysis, this technique criteria are valued by their similarity to ideal solution and the influence of each parameter or property is weighted according to their importance in the system of anchoring. Resins tested showed similar hardness values, however, the values of compressive stress at yield and compressive stress at break, and the maximum shear stress showed 30% greater differences. Furthermore, the results of pull out tests demonstrated significant differences for the calculated parameters. Finally, the resin more suitable for application on end fittings was selected by analyzing TOPSIS.
DOI: 10.6084/m9.figshare.6857960
title: Protección antiincrustante de estructuras sumergidas mediante recubrimientos formulados con 7-hidroxi-4-metilcumarina

description: ABSTRACT Biofouling settlement on submerged structures such as ships, buoys, farms, off-shore platforms and meteorological stations induces economic losses as a consequence of material deterioration and withdraw from service. Environmental regulations focus on the use of environmental friendly products to replace metallic biocides included in antifouling paints which are highly pollutant. A growing interest for searching and identifying efficient and benign antifoulants has being carried out. For this reason, the compound 7-hydroxy-4-methylcoumarin was synthesized following Green Chemistry procedures and then, characterized by current organic analysis. In the laboratory, antifouling activity of this coumarin was estimated by settlement test, i.e., batches of mussels (Mytilus edulis platensis) were exposed to different concentrations of the compound. Results indicated that coumarin was effective on both, settlement inhibition and byssal thread. Also, recovery tests were carried out; for this test, organisms were placed in clean seawater after coumarin exposure. It was demonstrated that coumarin effect was temporary because they could rapidly recover their vital parameters. Then, a soluble matrix antifouling paint containing this compound was formulated. Paints were applied on panels and exposed in Mar del Plata harbour for 45 and 90 days. Painted panels with this formulation showed a marked antifouling activity on conspicuous species of the community. Results indicated that sustainable chemistry-synthetized 7-hydroxy-4-methylcoumarin is a promising compound to be employed in antifouling paints due to its efficiency and low toxicity.
DOI: 10.6084/m9.figshare.6857960.v1
title: Protección antiincrustante de estructuras sumergidas mediante recubrimientos formulados con 7-hidroxi-4-metilcumarina

description: ABSTRACT Biofouling settlement on submerged structures such as ships, buoys, farms, off-shore platforms and meteorological stations induces economic losses as a consequence of material deterioration and withdraw from service. Environmental regulations focus on the use of environmental friendly products to replace metallic biocides included in antifouling paints which are highly pollutant. A growing interest for searching and identifying efficient and benign antifoulants has being carried out. For this reason, the compound 7-hydroxy-4-methylcoumarin was synthesized following Green Chemistry procedures and then, characterized by current organic analysis. In the laboratory, antifouling activity of this coumarin was estimated by settlement test, i.e., batches of mussels (Mytilus edulis platensis) were exposed to different concentrations of the compound. Results indicated that coumarin was effective on both, settlement inhibition and byssal thread. Also, recovery tests were carried out; for this test, organisms were placed in clean seawater after coumarin exposure. It was demonstrated that coumarin effect was temporary because they could rapidly recover their vital parameters. Then, a soluble matrix antifouling paint containing this compound was formulated. Paints were applied on panels and exposed in Mar del Plata harbour for 45 and 90 days. Painted panels with this formulation showed a marked antifouling activity on conspicuous species of the community. Results indicated that sustainable chemistry-synthetized 7-hydroxy-4-methylcoumarin is a promising compound to be employed in antifouling paints due to its efficiency and low toxicity.
DOI: 10.6084/m9.figshare.6857954
title: Synthesis and characterization of nanostructured TiO2 and TiO2/W thin films deposited by co-sputtering

description: ABSTRACT Nanostructured TiO2 and TiO2/W thin films were deposited on Corning glass substrates by RF and DC magnetron co-sputtering at room temperature, using three targets of TiO, Ti and W. After deposition, samples were subjected to an annealing treatment in air at 500 °C for 3 hrs. The effect of the annealing treatment and tungsten addition to the TiO2 matrix were studied by Raman spectroscopy and X-ray diffraction. Morphology and composition was studied with field emission scanning electron microscopy and optical characterization was made with UV-Vis spectroscopy. All the obtained samples presented an amorphous TiO2 phase; however, after the annealing treatment, a crystallization process from amorphous to anatase phase occurred with gain sizes between 15.6 and 18.3 nm, additionally, a small amount of rutile was also observable. The SEM images corroborated the XRD behavior, besides it was possible to calculate the thickness of the films which was greater for the W-doped films owing the extra power of the sputtering growth, and after the samples had the thermal treatment the thickness decreased due to a more organized structure. Finally, the UV-vis transmittance analysis revealed that the transmittance is higher in heat-treated films as compared to those without any thermal treatment; also, the TiO2 thin films showed a greater transmittance than the W doped TiO2 films, reaching 91%. The lack of transmittance in the non-thermal-treated films made it impossible to compute the band gap of the films; nevertheless, for the thermal-treated films the band gap had a minimal change to the classic TiO2 bang gap value, even for the W doped sample, providing them with the benefits of the tungsten within the same TiO2 structure due to a great homogenization on the structure.
DOI: 10.6084/m9.figshare.6857951
title: Creep behaviour of a polymer used for 3D printing

description: ABSTRACT In recent years, additive construction or 3D printing technology is being widely used for manufacturing goods. This construction procedure has and will have a great industrial impact. There are several 3D printing processes, and among of them the most known is called Fused Deposition Modeling (FDM). The objective of the present paper is oriented to the experimental characterization of the mechanical properties of pieces constructed by means of 3D printing using thermoplastic polymers. Although there are many studies about the characterization of mechanical properties in 3D printed parts, it should be noted that there is quite a little effort in evaluating the creep effect in 3D printed specimens. In this work the creep properties of the polylactic acid (PLA) are studied. This material is a thermoplastic and biodegradable biopolymer used in both amorphous and crystalline states, which has many technological applications. The tensile creep tests are performed at a temperature of 303K and at corresponding levels of tension between 25% and 50% of the yield strength of PLA. Standard specimens constructed with different layouts of plastic filament deposition are employed.
DOI: 10.6084/m9.figshare.6857945
title: Composite membranes: surface properties and thermal stability

description: ABSTRACT The composite membranes were manufactured with crosslinking poly(vinyl alcohol) on polyethersulfone porous membranes by coating process. PES membranes were exposed to air plasma for the purpose of surface modification. The coating of the support membrane was carried out by using a polymer matrix with a crosslinking agent. The physico-chemical properties have been studied by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) and contact angle measurements. Thermal stability properties and phases transition of the composite membranes were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Poly(vinyl alcohol) is water-soluble, hydrophilic and biodegradable polymer with excellent film forming properties. However, PVA must be crosslinked by modification reactions with a crosslinking agent to form a stable membrane with good mechanical properties in pervaporation. PVA was used as the dense polymer with maleic acid as a crosslinking agent. Fourier transformed infrared spectroscopy revealed the nature of the surface chemical. Contact angle measurements have been used for evaluating changes in wetting properties. The air-plasma treatment caused an effective surface modification. The mechanism responsible for the wettability improvement was the surface functionalization by insertion of polar groups. Introduction of maleic acid into the polymer chain increased the amorphous region of the membrane. The PVA is a semi-crystalline polymer exhibiting both a glass transition temperature (Tg) and a melting isotherm (Tm), as evidenced in the DSC thermogram. Thermal properties of the composite membranes were significantly enhanced. Both, the decomposition temperature and the residual weight increased when compared with dense PVA membranes. The chemically crosslinked PVA with maleic acid resulted in the formation of composite membranes with improved pervaporation properties for separation application.
DOI: 10.6084/m9.figshare.6857948
title: Influence of temperature on pull out tests on different steel-epoxy systems used in end fittings of flexible pipes

description: ABSTRACT In the offshore oil fields located in deep and ultra-deep waters they are used flexible pipes. In many cases inside these pipes, the hydrocarbons are transported at elevated temperatures. At the ends of the flexible pipes are installed end fittings, these are the connection with sea platforms and different subsea systems. In the assembly of end fittings, epoxy resin is used to embed the steel wires of the tensile armor and, in this way, form the anchorage system. Pull out tests allow to study the interaction between the materials that form the anchoring system. The aim of this work is to analyze the shear stress which tends to separate the joint composed to the epoxy resin and wire armor tensile of flexible pipe under different temperatures. Thus pull out tests are performed under two different temperatures (23 ° C and 100 ° C) in samples made with three different epoxies. Were analyzed two values of shear stress calculated in different phases of the test, one that is dependent on the polymer adhesion to steel, and the other is dependent on the friction between the materials. For each of the cases using ANOVA analysis, it was determinate that the temperature increase affects the two parameters studied decreasing its value and this is repeated for the three resins evaluated. Furthermore it was observed that the resins with inorganic and aluminum filler were less affected with respect which had not those fillers. This study show the importance of selection and application appropriate of epoxy materials used inside of the end fittings, because a failure is very dangerous to the environment and production.
DOI: 10.6084/m9.figshare.6857951.v1
title: Creep behaviour of a polymer used for 3D printing

description: ABSTRACT In recent years, additive construction or 3D printing technology is being widely used for manufacturing goods. This construction procedure has and will have a great industrial impact. There are several 3D printing processes, and among of them the most known is called Fused Deposition Modeling (FDM). The objective of the present paper is oriented to the experimental characterization of the mechanical properties of pieces constructed by means of 3D printing using thermoplastic polymers. Although there are many studies about the characterization of mechanical properties in 3D printed parts, it should be noted that there is quite a little effort in evaluating the creep effect in 3D printed specimens. In this work the creep properties of the polylactic acid (PLA) are studied. This material is a thermoplastic and biodegradable biopolymer used in both amorphous and crystalline states, which has many technological applications. The tensile creep tests are performed at a temperature of 303K and at corresponding levels of tension between 25% and 50% of the yield strength of PLA. Standard specimens constructed with different layouts of plastic filament deposition are employed.
DOI: 10.6084/m9.figshare.6857945.v1
title: Composite membranes: surface properties and thermal stability

description: ABSTRACT The composite membranes were manufactured with crosslinking poly(vinyl alcohol) on polyethersulfone porous membranes by coating process. PES membranes were exposed to air plasma for the purpose of surface modification. The coating of the support membrane was carried out by using a polymer matrix with a crosslinking agent. The physico-chemical properties have been studied by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) and contact angle measurements. Thermal stability properties and phases transition of the composite membranes were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Poly(vinyl alcohol) is water-soluble, hydrophilic and biodegradable polymer with excellent film forming properties. However, PVA must be crosslinked by modification reactions with a crosslinking agent to form a stable membrane with good mechanical properties in pervaporation. PVA was used as the dense polymer with maleic acid as a crosslinking agent. Fourier transformed infrared spectroscopy revealed the nature of the surface chemical. Contact angle measurements have been used for evaluating changes in wetting properties. The air-plasma treatment caused an effective surface modification. The mechanism responsible for the wettability improvement was the surface functionalization by insertion of polar groups. Introduction of maleic acid into the polymer chain increased the amorphous region of the membrane. The PVA is a semi-crystalline polymer exhibiting both a glass transition temperature (Tg) and a melting isotherm (Tm), as evidenced in the DSC thermogram. Thermal properties of the composite membranes were significantly enhanced. Both, the decomposition temperature and the residual weight increased when compared with dense PVA membranes. The chemically crosslinked PVA with maleic acid resulted in the formation of composite membranes with improved pervaporation properties for separation application.
DOI: 10.6084/m9.figshare.6857948.v1
title: Influence of temperature on pull out tests on different steel-epoxy systems used in end fittings of flexible pipes

description: ABSTRACT In the offshore oil fields located in deep and ultra-deep waters they are used flexible pipes. In many cases inside these pipes, the hydrocarbons are transported at elevated temperatures. At the ends of the flexible pipes are installed end fittings, these are the connection with sea platforms and different subsea systems. In the assembly of end fittings, epoxy resin is used to embed the steel wires of the tensile armor and, in this way, form the anchorage system. Pull out tests allow to study the interaction between the materials that form the anchoring system. The aim of this work is to analyze the shear stress which tends to separate the joint composed to the epoxy resin and wire armor tensile of flexible pipe under different temperatures. Thus pull out tests are performed under two different temperatures (23 ° C and 100 ° C) in samples made with three different epoxies. Were analyzed two values of shear stress calculated in different phases of the test, one that is dependent on the polymer adhesion to steel, and the other is dependent on the friction between the materials. For each of the cases using ANOVA analysis, it was determinate that the temperature increase affects the two parameters studied decreasing its value and this is repeated for the three resins evaluated. Furthermore it was observed that the resins with inorganic and aluminum filler were less affected with respect which had not those fillers. This study show the importance of selection and application appropriate of epoxy materials used inside of the end fittings, because a failure is very dangerous to the environment and production.
DOI: 10.6084/m9.figshare.6857939
title: Carcass and body components of suckling lambs grazing ryegrass and supplemented with legume or concentrate

description: ABSTRACT This research objective was to evaluate the effect of private supplementation with concentrated or legumes, on the carcass characteristics and body components from suckling lambs kept on ryegrass pasture. Twenty seven suckling lambs were used, with about 17 days of age and weighing 9,91±0,594kg, which were distributed in the treatments that corresponded to feeding systems: suckling lambs kept on ryegrass pasture, suckling lambs kept on ryegrass pasture and supplemented with concentrated in private feeder (creep feeding) and suckling lambs kept on ryegrass pasture and supplemented with legume in the private pasture (creep grazing). The concentrate supplement was composed by corn, soybean meal and limestone, and was supplied ad libitum. The supplementary pasture was white clover legume. The experimental design was completely randomized, where the results were submitted to analysis of variance and means compared by Tukey test at 5% of significance level. The gastrointestinal+bile+urine content and the proportion of esophagus were higher (P&lt;0,05) in lambs kept on ryegrass. The liver and large intestine proportions were higher (P&lt;0,05) in lambs supplemented with concentrate. The tested alimentary systems produce carcasses with similar characteristics. The supplementation with legume or concentrate cause changes in body components of suckling lambs grazing ryegrass.
DOI: 10.6084/m9.figshare.6857942
title: Effect of MTMO silane concentration on electrogalvanized steel in the protection against corrosion

description: ABSTRACT Superficial pretreatments based on silanes are one of the prominent alternatives to replace chromates as temporary protectors from the action of aggressive environments to metallic substrates. The barrier effect afforded by the silane film makes porosity, thickness and film homogeneity important issues in the protective effect. In the present work, the influence of the concentration and amount of layers of mercaptopropyltrimethoxysilane (MTMO) applied on electrogalvanized steel on its corrosion behavior was evaluated. Before silane application the substrate was degreased by immersion in toluene for 2 min at 40 ºC. The surface sample was activated by immersion in NaOH 10% p/v and applying a cathodic current density of 0,12 A/cm2, the temperature was controlled at 40 ºC. MTMO was prepared adding 2 or 4 % v/v of MTMO to a distilled water/methanol (3:2v/v, pH adjusted to 4 with acetic acid), and hydrolyzed for 60 min; some samples were coated with 1 layer of MTMO and others with 2 layers. All the coatings were cured at 80 ºC for 10 min. The coating’s porosity was evaluated by cyclic voltammetry and reaction to copper sulphate, its thickness and morphology by SEM-EDS and the corrosion behavior by polarization curves, electrochemical impedance spectroscopy and exposure into a temperature and humidity controlled-chamber. The results showed that the protective capacity afforded by 2 layers of MTMO is higher than that obtained by raising the silane concentration. Besides, the variables under study affect the morphology and the thickness of the protective layer.