cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6857984
title: Influence of calcium in moisture retention clay

description: ABSTRACT Bentonite as a raw material is an economical alternative to produce desiccants. The literature indicates that it is a good water adsorbent in relation to the desiccants commonly used in industry (silica gel, molecular sieve). In this sense, it is a valid alternative and an economic option since the clay is a natural compound, which makes it environmentally friendly. In this way, it is possible to protect products from moisture with the addi-tional advantage that its desiccant capacity remains practically constant after successive cycles of adsorption - regeneration, using low temperatures (100°C) for the latter process. Considering the interest of increasing the exploitation of bentonite in Argentina, previous studies evaluated its retention capacity, using, among others, a Patagonian bentonite. The adsorption of water vapor is affected by the concentration of the smectite clay mineral, the relative humidity, the drying of the samples, and the type of interlaminar cation of the smectite. In the present work it is determined that there is an increase of adsorption in relation to the starting material after the addition of increasing concentrations of Ca by ion exchange. In these samples the adsorption is carried out mainly by the hydrated ion present in the interlaminar space. Also, the desiccant materials benton-ite-Ca showed structural and textural differences in relation to natural bentonite.
DOI: 10.6084/m9.figshare.6857987
title: Effect of bentonite addition on the optical properties of different polymeric composites materials

description: ABSTRACT In this work, composite materials were obtained by the incorporation of bentonite to biodegradable and synthetic polymeric matrices. Commercial (BE) and natural (BM) bentonite samples were employed, as well as three different polymeric matrices: thermoplastic corn starch (TPS), high density polyethylene (HDPE) and a poly(styrene-b-butadiene-b-styrene) triblock copolymer (SBS). Composite materials were obtained by incorporating 5 % w/w filler by melt mixing. Films were obtained by thermo-compression in a hydraulic press. By Scanning Electron Microscopy (SEM) it were examined the homogeneity and appearance of films. Opacity and UV barrier capacity were determined from the UV-vis spectra recorded in a spectrophotometer. Film color measurements were performed using a colorimeter in the transmittance mode, recording parameters L, a, and b. From SEM micrographs, a good filler distribution in the three different matrices were observed. The addition of bentonite modified the optical properties of films due to their blocking effect, evidenced in an increase in both UV barrier capacity and opacity.
DOI: 10.6084/m9.figshare.6857987.v1
title: Effect of bentonite addition on the optical properties of different polymeric composites materials

description: ABSTRACT In this work, composite materials were obtained by the incorporation of bentonite to biodegradable and synthetic polymeric matrices. Commercial (BE) and natural (BM) bentonite samples were employed, as well as three different polymeric matrices: thermoplastic corn starch (TPS), high density polyethylene (HDPE) and a poly(styrene-b-butadiene-b-styrene) triblock copolymer (SBS). Composite materials were obtained by incorporating 5 % w/w filler by melt mixing. Films were obtained by thermo-compression in a hydraulic press. By Scanning Electron Microscopy (SEM) it were examined the homogeneity and appearance of films. Opacity and UV barrier capacity were determined from the UV-vis spectra recorded in a spectrophotometer. Film color measurements were performed using a colorimeter in the transmittance mode, recording parameters L, a, and b. From SEM micrographs, a good filler distribution in the three different matrices were observed. The addition of bentonite modified the optical properties of films due to their blocking effect, evidenced in an increase in both UV barrier capacity and opacity.
DOI: 10.6084/m9.figshare.6857981
title: Acoustic Emission monitoring of high-strength concrete beams with and without fibers exposed to high temperature

description: ABSTRACT The addition of fibers to the cementitious matrix, giving rise to fiber-reinforced concrete, aims to improve the low ductility observed in concrete mechanical response under different load scenarios, particularly under direct tension. In this work, cracking and mechanical degradation processes of concrete elements using acoustic emission technique are examined, with the objective of analyzing the incidence of high temperatures on the failure behavior of high-strength concrete beams with and without fibers. Results of an experimental campaign including different mechanical tests on concrete specimens with and without the addition of a hybrid combination of steel and polypropylene fibers are presented. The incorporation of polypropylene fibers is intended to improve the behavior of concrete against elevated temperatures. The evolution of acoustic emission measurements during bending tests and its relation with the mechanical response is analyzed. It is observed that after being exposed to a temperature of 600°C, properties of fiber reinforced concrete were relatively less affected than those of plain concrete, retaining some capacity to absorb energy in the post-peak regime. It is also confirmed that the monitoring technique used, has a direct correlation with the degradation process of concrete.
DOI: 10.6084/m9.figshare.6857981.v1
title: Acoustic Emission monitoring of high-strength concrete beams with and without fibers exposed to high temperature

description: ABSTRACT The addition of fibers to the cementitious matrix, giving rise to fiber-reinforced concrete, aims to improve the low ductility observed in concrete mechanical response under different load scenarios, particularly under direct tension. In this work, cracking and mechanical degradation processes of concrete elements using acoustic emission technique are examined, with the objective of analyzing the incidence of high temperatures on the failure behavior of high-strength concrete beams with and without fibers. Results of an experimental campaign including different mechanical tests on concrete specimens with and without the addition of a hybrid combination of steel and polypropylene fibers are presented. The incorporation of polypropylene fibers is intended to improve the behavior of concrete against elevated temperatures. The evolution of acoustic emission measurements during bending tests and its relation with the mechanical response is analyzed. It is observed that after being exposed to a temperature of 600°C, properties of fiber reinforced concrete were relatively less affected than those of plain concrete, retaining some capacity to absorb energy in the post-peak regime. It is also confirmed that the monitoring technique used, has a direct correlation with the degradation process of concrete.
DOI: 10.6084/m9.figshare.6857984.v1
title: Influence of calcium in moisture retention clay

description: ABSTRACT Bentonite as a raw material is an economical alternative to produce desiccants. The literature indicates that it is a good water adsorbent in relation to the desiccants commonly used in industry (silica gel, molecular sieve). In this sense, it is a valid alternative and an economic option since the clay is a natural compound, which makes it environmentally friendly. In this way, it is possible to protect products from moisture with the addi-tional advantage that its desiccant capacity remains practically constant after successive cycles of adsorption - regeneration, using low temperatures (100°C) for the latter process. Considering the interest of increasing the exploitation of bentonite in Argentina, previous studies evaluated its retention capacity, using, among others, a Patagonian bentonite. The adsorption of water vapor is affected by the concentration of the smectite clay mineral, the relative humidity, the drying of the samples, and the type of interlaminar cation of the smectite. In the present work it is determined that there is an increase of adsorption in relation to the starting material after the addition of increasing concentrations of Ca by ion exchange. In these samples the adsorption is carried out mainly by the hydrated ion present in the interlaminar space. Also, the desiccant materials benton-ite-Ca showed structural and textural differences in relation to natural bentonite.
DOI: 10.6084/m9.figshare.6857975
title: Changes in the crystalline degree in neutron irradiated EPDM viewed through infrared spectroscopy and inelastic neutron scattering

description: ABSTRACT The changes in the degree of crystallinity in commercial Ethylene Propylene Diene rubber-type M (EPDM) irradiated with neutrons at different doses has been studied by means of inelastic neutron scattering and infrared absorption spectroscopy experiments. EPDM samples were taken from the housing of non-ceramic electrical insulators which are used in outdoor transmission lines of 66 kV. Inelastic neutron scattering spectra were recorded at 5 K with an accessible energy-transfer range between 180 - 3500 cm-1. Infrared studies were performed at room temperature with an energy transfer between 4000 - 400 cm-1. Controlled neutron irradiation allows to obtain different volume fraction and size of crystalline zones in EPDM. The obtained results are discussed and correlated with studies of differential scanning calorimetry, dynamic mechanical analysis and positron annihilation lifetime spectroscopy from where the changes in crystallinity in EPDM were indirectly studied. Inelastic neutron scattering studies were not appropriate for determining the changes in the crystallinity degree in neutron irradiated commercial EPDM. In contrast, from infrared absorption spectroscopy the changes in crystallinity could be determined successfully.
DOI: 10.6084/m9.figshare.6857978
title: Autochthonous probiotic mixture improves biometrical parameters of larvae of Piaractus mesopotamicus (Caracidae, Characiforme, Teleostei)

description: ABSTRACT: Probiotics are a novel alternative to antibiotics as growth factors. Previously, our group isolated, selected and tested in vivo, eight autochthonous strains. They showed no significant effects when administered individually. However, the best doses, stages and ways of administration were combined in a multi strain formula. The aim of this research was to evaluate the effect of this probiotic product on the growth and survival of Piaractus mesopotamicus larvae. The administration was implemented during egg incubation and endogenous feeding period (5), during larvae exogenous feeding period (10) and all along the experiment (15). A group without microorganisms was used as control. The probiotic generates significant increments of mean weight and not significant increases of survival and biomass in two of the three tested stages. These results demonstrate the effectiveness of an autochthonous probiotic formula for the culture of this native fish species.
DOI: 10.6084/m9.figshare.6857978.v1
title: Autochthonous probiotic mixture improves biometrical parameters of larvae of Piaractus mesopotamicus (Caracidae, Characiforme, Teleostei)

description: ABSTRACT: Probiotics are a novel alternative to antibiotics as growth factors. Previously, our group isolated, selected and tested in vivo, eight autochthonous strains. They showed no significant effects when administered individually. However, the best doses, stages and ways of administration were combined in a multi strain formula. The aim of this research was to evaluate the effect of this probiotic product on the growth and survival of Piaractus mesopotamicus larvae. The administration was implemented during egg incubation and endogenous feeding period (5), during larvae exogenous feeding period (10) and all along the experiment (15). A group without microorganisms was used as control. The probiotic generates significant increments of mean weight and not significant increases of survival and biomass in two of the three tested stages. These results demonstrate the effectiveness of an autochthonous probiotic formula for the culture of this native fish species.
DOI: 10.6084/m9.figshare.6857972
title: Ad hoc methodology for observation wear and fracture surfaces

description: ABSTRACT In the present work, a methodology of microscopic analysis and measurement of wear surfaces is presented, based on images made using digital processing techniques such as stitching and stac-king. The images are obtained from an ad-hoc and low-cost microscopic observation system, consisting of sample positioning and focus-elevation modules with micrometric resolution. The objective of the work is to gather as much information in a single image. The creation of permanent photographic documentation has the advantage of analyzing a surface without danger of manipulating a sample. It was observed that the methodology used was satisfactory for the determination of surface characteristics and measurements for calculation of wear rate in block on ring tests, as well as for some fracture analysis.
DOI: 10.6084/m9.figshare.6857975.v1
title: Changes in the crystalline degree in neutron irradiated EPDM viewed through infrared spectroscopy and inelastic neutron scattering

description: ABSTRACT The changes in the degree of crystallinity in commercial Ethylene Propylene Diene rubber-type M (EPDM) irradiated with neutrons at different doses has been studied by means of inelastic neutron scattering and infrared absorption spectroscopy experiments. EPDM samples were taken from the housing of non-ceramic electrical insulators which are used in outdoor transmission lines of 66 kV. Inelastic neutron scattering spectra were recorded at 5 K with an accessible energy-transfer range between 180 - 3500 cm-1. Infrared studies were performed at room temperature with an energy transfer between 4000 - 400 cm-1. Controlled neutron irradiation allows to obtain different volume fraction and size of crystalline zones in EPDM. The obtained results are discussed and correlated with studies of differential scanning calorimetry, dynamic mechanical analysis and positron annihilation lifetime spectroscopy from where the changes in crystallinity in EPDM were indirectly studied. Inelastic neutron scattering studies were not appropriate for determining the changes in the crystallinity degree in neutron irradiated commercial EPDM. In contrast, from infrared absorption spectroscopy the changes in crystallinity could be determined successfully.
DOI: 10.6084/m9.figshare.6857969
title: Performance of segmented diamond discs in concrete cutting

description: ABSTRACT Segmented diamond discs are used in cutting abrasive and fragile materials, such as masonry, concrete and marble. Their constant evolution over the past 15 years has allowed increasing the effectiveness of these operations. However, despite being widely used, there is still no standard test to assess their performance in representative conditions of a normal service. In this work a complete procedure to evaluate the disc performance is presented. To that end it was necessary to develop: a Computer Numeric Control (CNC) cutting machine, a test material, the operating conditions, the stopping criterion, and the evaluation methods (wear and depth of cut). Four brands of segmented diamond discs of 115 mm of diameter, nominated A, B, C and D respectively, were tested three times. . The tests were made cutting 45 prismatic blocks of concrete, 290 x 260 x 75 mm in size. As for the wear, the discs in groups A and D showed similar performance, while group B scored last , and group C scored best. As regards to the aptitude to cut major depths, groups A and B showed better performance. When the behavior of the discs was evaluated by the depth of cut to wear ratio, the best performance was achieved with group C. In accordance with the obtained results, it is possible to affirm that, the methods of diametral change and weight loss used to quantify the wear of the discs, can be considered equivalent. Finally, the observation of the cut surfaces of this type of discs, using Scanning Electron Microscopy, allows justifying the cutting capability observed during the tests.
DOI: 10.6084/m9.figshare.6857972.v1
title: Ad hoc methodology for observation wear and fracture surfaces

description: ABSTRACT In the present work, a methodology of microscopic analysis and measurement of wear surfaces is presented, based on images made using digital processing techniques such as stitching and stac-king. The images are obtained from an ad-hoc and low-cost microscopic observation system, consisting of sample positioning and focus-elevation modules with micrometric resolution. The objective of the work is to gather as much information in a single image. The creation of permanent photographic documentation has the advantage of analyzing a surface without danger of manipulating a sample. It was observed that the methodology used was satisfactory for the determination of surface characteristics and measurements for calculation of wear rate in block on ring tests, as well as for some fracture analysis.
DOI: 10.6084/m9.figshare.6857963
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
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.6857969.v1
title: Performance of segmented diamond discs in concrete cutting

description: ABSTRACT Segmented diamond discs are used in cutting abrasive and fragile materials, such as masonry, concrete and marble. Their constant evolution over the past 15 years has allowed increasing the effectiveness of these operations. However, despite being widely used, there is still no standard test to assess their performance in representative conditions of a normal service. In this work a complete procedure to evaluate the disc performance is presented. To that end it was necessary to develop: a Computer Numeric Control (CNC) cutting machine, a test material, the operating conditions, the stopping criterion, and the evaluation methods (wear and depth of cut). Four brands of segmented diamond discs of 115 mm of diameter, nominated A, B, C and D respectively, were tested three times. . The tests were made cutting 45 prismatic blocks of concrete, 290 x 260 x 75 mm in size. As for the wear, the discs in groups A and D showed similar performance, while group B scored last , and group C scored best. As regards to the aptitude to cut major depths, groups A and B showed better performance. When the behavior of the discs was evaluated by the depth of cut to wear ratio, the best performance was achieved with group C. In accordance with the obtained results, it is possible to affirm that, the methods of diametral change and weight loss used to quantify the wear of the discs, can be considered equivalent. Finally, the observation of the cut surfaces of this type of discs, using Scanning Electron Microscopy, allows justifying the cutting capability observed during the tests.