Isabel Padilla - Academia.edu (original) (raw)

Papers by Isabel Padilla

Research paper thumbnail of β-Cyclodextrin-modified zeolite from fly ash: Synthesis, characterization, and use as cadmium, lead and zinc adsorbent

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Research paper thumbnail of Proceso de microencapsulación de mercurio líquido mediante tecnología de estabilización/solidificación con azufre polimérico. Parte I: Caracterización de materiales

Revista De Metalurgia, Feb 28, 2012

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Research paper thumbnail of Reduction of iron oxide in hydrogen atmosphere by using concentrated solar energy: preliminary study

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Research paper thumbnail of Use of concentrated solar energy to synthesize alumina from an aluminium hazardous waste

Twenty-Eighth International Conference on Solid Waste Technology and Management. Filadelfia, PA, USA

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Research paper thumbnail of Determination for ICP-MS of phosphorus in steels using segmented-flow injection

Trabajo presentado en el European Winter Conference on Plasma Spectrochemistry, celebrado en Gant... more Trabajo presentado en el European Winter Conference on Plasma Spectrochemistry, celebrado en Gante (Bélgica), del 12 al 17 de enero de 199

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Research paper thumbnail of Hydrotalcites prepared with different coprecipitant agents and a hazardous aluminium waste. Effects on porosity

International Conference on Sustainable Materials Science and Technology, Paris, Fr. Comunicacion... more International Conference on Sustainable Materials Science and Technology, Paris, Fr. Comunicacion Oral

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Research paper thumbnail of High spatial resolution analysis of steel samples using laser ablation ICP-MS

Europace, 2006

Introduction The LA-ICP-MS technique has been evaluated with respect to applications relevant for... more Introduction The LA-ICP-MS technique has been evaluated with respect to applications relevant for the steel industry, with special emphasis on spatially resolved analysis. Three different commercially available laser ablation units have been used, CETAC LSX 100, CETAC LSX 200 and New Wave Research UP 213. These are all based on NdYAG lasers combined with frequency doubling and frequency mixing crystals in order to obtain UV laser output. The CETAC systems operate at 266 nm, the New Wave system at 213 nm. In addition, some investigations have been carried out using specially designed systems with excimer lasers. The different laser ablation units are coupled to ICP-MS systems with mass analysers of different types, a quadropole, a time-of-flight (TOF) and a magnetic sector system. Samples and sample preparation A number of samples were selected and prepared for different parts of the investigations. For the lateral resolution studies, special welded samples of different steel alloys ...

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Research paper thumbnail of Zero-waste process for the transformation of a hazardous aluminum waste into a raw material to obtain zeolites

Journal of Cleaner Production, 2020

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Research paper thumbnail of Slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for steelmaking flue dust analysis

Spectrochimica Acta Part B: Atomic Spectroscopy, 2000

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Research paper thumbnail of Evaluation of different sample introduction approaches for the determination of boron in unalloyed steels by inductively coupled plasma mass spectrometry

Spectrochimica Acta Part B: Atomic Spectroscopy, 2005

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Research paper thumbnail of Estudio del envejecimiento acelerado bajo radiación solar concentrada de vidrios de oxicarburo como receptores de alta temperatura

Revista de Materiales Compuestos

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Research paper thumbnail of Study of five hydraulic dam sludges from Argelia as pozzolanic materials

E3D 2012, Eau, Dechets et Developpment Durable Congres. Agadir, MarruecosThis paper reports the s... more E3D 2012, Eau, Dechets et Developpment Durable Congres. Agadir, MarruecosThis paper reports the study of the pozzolanic properties of sludges from different hydraulic dams from Algeria compared with normalized pozzolans, such as silica fume and fly ash. The study of the pozzolanic activity was carried out by an accelerated method of saturated lime solution, based on the Frattini method for pozzolanic cements. The results showed that one of the studied sludge (SLD5) is more active than silica fume (a very reactive pozzolan) at 28 days of reaction. The rest of sludges (SLD1-SLD4) show also high pozzolanic activity and consumed about 61-78% of the available lime at 28 days of pozzolanic reaction. The blended cements made with 20% of this waste showed compressive strength lower than the obtained by reference ordinary Portland cement (OPC) due to the dilution effect provokes by pozzolans, but SLD5 obtain a higher value of compressive strength at long ages of curing (90 days).N

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Research paper thumbnail of Development of Lightweight Mortars Using Sustainable Low-Density Glass Aggregates from Secondary Raw Materials

Materials

In this study, different lightweight expanded glass aggregates (LEGAs) were produced from glass c... more In this study, different lightweight expanded glass aggregates (LEGAs) were produced from glass cullet and various carbonated wastes, through a thermal impact process. The effects of LEGA microstructure and morphology on both the adherence to the cement paste and the mechanical properties of mortars after 28 days of curing were studied. The properties of lightweight mortars made of either LEGAs or expanded clay aggregates were compared. The results demonstrated the feasibility of using LEGAs to produce glass lightweight aggregate mortar, with flexural and compressive strength values ranging from 5.5 to 8.2 MPa and from 28.1 to 47.6 MPa, respectively. The differences in mechanical properties were explained according to the microstructures of the fracture surfaces. Thus, arlite-type ceramic aggregates presented surface porosities that allowed mortar intrusion and the formation of an interconnected interface; although the surfaces of the vitreous aggregates were free from porosity due ...

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Research paper thumbnail of Kinetic study of the transformation of sodalite to nepheline

Journal of the American Ceramic Society, 2022

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Research paper thumbnail of Evaluation of thermal shock resistance of silicon oxycarbide materials for high-temperature receiver applications

Solar Energy, 2018

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Research paper thumbnail of Recovery of chromium(VI) from hydrochloric acid liquors using the resin Dowex 1x8

Journal of Chemical Research, 2002

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Research paper thumbnail of Study of the application of air-water flow injection inductively coupled plasma mass spectrometry for the determination of calcium in steels

Journal of Analytical Atomic Spectrometry, 1996

ABSTRACT This paper describes a methodology for the determination of Ca, an important element in ... more ABSTRACT This paper describes a methodology for the determination of Ca, an important element in the process of steel making. Determination of Ca is typically problematic when using ICP-MS because of the 40Ar interference on the most abundant Ca isotope. In the present study the use of the 44Ca isotope for ICP-MS measurement was considered. To dissolve the samples, a microwave digestion system was applied to guarantee the total dissolution of the Ca compounds, thus minimizing the sample preparation time, the amounts of reagents used and the risk of contamination. Carbon and Si, normally present in steel samples, were eliminated by treatment with H2SO4 and HF to avoid 12C16O2 and 28Si16O isobaric interferences on the 44Ca isotope. After matrix removal by the use of mercury cathode electrolysis, air–water FI-ICP-MS was used for the determination of Ca. Scandium, with an ionization potential and mass number close to those of Ca, was used as an internal standard for quantitative measurements. The operating parameters for air-water FI-ICP-MS were optimized with respect to signal peak height intensities, stability and matrix effect. The detection limit obtained was 0.6 µg g–1 and the RSD value, calculated from ten replicates of a 200 µl injection of a 50 µg l–1 Ca solution spiked with 2 µg l–1 of Sc, was 0.7%. Data are presented for four certified reference steel materials: JSS 169–5 and 171–5, from Japanese Standards of Iron and Steel; and ECRMs 195–1 (Cr–Ni–steel) and 096 (low-S, low-Ca steel), from the Bureau of Analysed Samples.

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Research paper thumbnail of Dispersion-Free Solvent Extraction of Cr(VI) from Acidic Solutions Using Hollow Fiber Contactor

Environmental Science & Technology, 2009

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Research paper thumbnail of Spark Ablation Inductively Coupled Plasma Mass Spectrometry Applied to the Semi-Quantitative Panoramic Analysis of Ferroalloys

Applied Spectroscopy, 2000

The coupling of inductively coupled plasma mass spectrometry (ICP-MS) with spark ablation (SA) wa... more The coupling of inductively coupled plasma mass spectrometry (ICP-MS) with spark ablation (SA) was applied for the semi-quantitative determination of impurities in different types of ferroalloys. The sparking operating conditions were optimized, and a restrictive path including a cyclone and a spray chamber was used to decrease the quantity of sparked material reaching the plasma, to prevent torch injector and sampling cone blockage. Samples were mixed in a 1:2 sample-to-graphite ratio and pressed into pellets for direct solid sampling by the spark. The advantage of the technique includes the benefit of easily determining some refractory elements that are very difficult to dissolve. The method was tested on three different types of ferroalloys: Fe-Ti, Fe-Nb, and Fe-V. A single standard ferroalloy sample was used as an external calibration sample to create a complete response curve for each type of ferroalloy base. Industrial ferroalloys, chemically characterized by using different a...

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Research paper thumbnail of Use of a Waste-Derived Linde Type-A Immobilized in Agarose for the Remediation of Water Impacted by Coal Acid Mine Drainage at Pilot Scale

Materials

A new adsorbent based on an immobilized waste-derived LTA zeolite in agarose (AG) has proven to b... more A new adsorbent based on an immobilized waste-derived LTA zeolite in agarose (AG) has proven to be an innovative and efficient alternative for removing metallic contaminants from water impacted by acid mine drainage (AMD) because the immobilization prevents the solubilization of the zeolite in acidic media and eases its separation from the adsorbed solution. A pilot device was developed containing slices of the sorbent material [AG (1.5%)–LTA (8%)] to be used in a treatment system under an upward continuous flow. High removals of Fe2+ (93.45%), Mn2+ (91.62%), and Al3+ (96.56%) were achieved, thus transforming river water heavily contaminated by metallic ions into water suitable for non-potable use for these parameters, according to Brazilian and/or FAO standards. Breakthrough curves were constructed and the corresponding maximum adsorption capacities (mg/g) (Fe2+, 17.42; Mn2+, 1.38; Al3+, 15.20) calculated from them. Thomas mathematical model was well fitted to the experimental data...

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Research paper thumbnail of β-Cyclodextrin-modified zeolite from fly ash: Synthesis, characterization, and use as cadmium, lead and zinc adsorbent

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Proceso de microencapsulación de mercurio líquido mediante tecnología de estabilización/solidificación con azufre polimérico. Parte I: Caracterización de materiales

Revista De Metalurgia, Feb 28, 2012

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Research paper thumbnail of Reduction of iron oxide in hydrogen atmosphere by using concentrated solar energy: preliminary study

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Use of concentrated solar energy to synthesize alumina from an aluminium hazardous waste

Twenty-Eighth International Conference on Solid Waste Technology and Management. Filadelfia, PA, USA

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Determination for ICP-MS of phosphorus in steels using segmented-flow injection

Trabajo presentado en el European Winter Conference on Plasma Spectrochemistry, celebrado en Gant... more Trabajo presentado en el European Winter Conference on Plasma Spectrochemistry, celebrado en Gante (Bélgica), del 12 al 17 de enero de 199

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Hydrotalcites prepared with different coprecipitant agents and a hazardous aluminium waste. Effects on porosity

International Conference on Sustainable Materials Science and Technology, Paris, Fr. Comunicacion... more International Conference on Sustainable Materials Science and Technology, Paris, Fr. Comunicacion Oral

Bookmarks Related papers MentionsView impact

Research paper thumbnail of High spatial resolution analysis of steel samples using laser ablation ICP-MS

Europace, 2006

Introduction The LA-ICP-MS technique has been evaluated with respect to applications relevant for... more Introduction The LA-ICP-MS technique has been evaluated with respect to applications relevant for the steel industry, with special emphasis on spatially resolved analysis. Three different commercially available laser ablation units have been used, CETAC LSX 100, CETAC LSX 200 and New Wave Research UP 213. These are all based on NdYAG lasers combined with frequency doubling and frequency mixing crystals in order to obtain UV laser output. The CETAC systems operate at 266 nm, the New Wave system at 213 nm. In addition, some investigations have been carried out using specially designed systems with excimer lasers. The different laser ablation units are coupled to ICP-MS systems with mass analysers of different types, a quadropole, a time-of-flight (TOF) and a magnetic sector system. Samples and sample preparation A number of samples were selected and prepared for different parts of the investigations. For the lateral resolution studies, special welded samples of different steel alloys ...

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Research paper thumbnail of Zero-waste process for the transformation of a hazardous aluminum waste into a raw material to obtain zeolites

Journal of Cleaner Production, 2020

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for steelmaking flue dust analysis

Spectrochimica Acta Part B: Atomic Spectroscopy, 2000

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluation of different sample introduction approaches for the determination of boron in unalloyed steels by inductively coupled plasma mass spectrometry

Spectrochimica Acta Part B: Atomic Spectroscopy, 2005

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Estudio del envejecimiento acelerado bajo radiación solar concentrada de vidrios de oxicarburo como receptores de alta temperatura

Revista de Materiales Compuestos

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Study of five hydraulic dam sludges from Argelia as pozzolanic materials

E3D 2012, Eau, Dechets et Developpment Durable Congres. Agadir, MarruecosThis paper reports the s... more E3D 2012, Eau, Dechets et Developpment Durable Congres. Agadir, MarruecosThis paper reports the study of the pozzolanic properties of sludges from different hydraulic dams from Algeria compared with normalized pozzolans, such as silica fume and fly ash. The study of the pozzolanic activity was carried out by an accelerated method of saturated lime solution, based on the Frattini method for pozzolanic cements. The results showed that one of the studied sludge (SLD5) is more active than silica fume (a very reactive pozzolan) at 28 days of reaction. The rest of sludges (SLD1-SLD4) show also high pozzolanic activity and consumed about 61-78% of the available lime at 28 days of pozzolanic reaction. The blended cements made with 20% of this waste showed compressive strength lower than the obtained by reference ordinary Portland cement (OPC) due to the dilution effect provokes by pozzolans, but SLD5 obtain a higher value of compressive strength at long ages of curing (90 days).N

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Development of Lightweight Mortars Using Sustainable Low-Density Glass Aggregates from Secondary Raw Materials

Materials

In this study, different lightweight expanded glass aggregates (LEGAs) were produced from glass c... more In this study, different lightweight expanded glass aggregates (LEGAs) were produced from glass cullet and various carbonated wastes, through a thermal impact process. The effects of LEGA microstructure and morphology on both the adherence to the cement paste and the mechanical properties of mortars after 28 days of curing were studied. The properties of lightweight mortars made of either LEGAs or expanded clay aggregates were compared. The results demonstrated the feasibility of using LEGAs to produce glass lightweight aggregate mortar, with flexural and compressive strength values ranging from 5.5 to 8.2 MPa and from 28.1 to 47.6 MPa, respectively. The differences in mechanical properties were explained according to the microstructures of the fracture surfaces. Thus, arlite-type ceramic aggregates presented surface porosities that allowed mortar intrusion and the formation of an interconnected interface; although the surfaces of the vitreous aggregates were free from porosity due ...

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Research paper thumbnail of Kinetic study of the transformation of sodalite to nepheline

Journal of the American Ceramic Society, 2022

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluation of thermal shock resistance of silicon oxycarbide materials for high-temperature receiver applications

Solar Energy, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Recovery of chromium(VI) from hydrochloric acid liquors using the resin Dowex 1x8

Journal of Chemical Research, 2002

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Study of the application of air-water flow injection inductively coupled plasma mass spectrometry for the determination of calcium in steels

Journal of Analytical Atomic Spectrometry, 1996

ABSTRACT This paper describes a methodology for the determination of Ca, an important element in ... more ABSTRACT This paper describes a methodology for the determination of Ca, an important element in the process of steel making. Determination of Ca is typically problematic when using ICP-MS because of the 40Ar interference on the most abundant Ca isotope. In the present study the use of the 44Ca isotope for ICP-MS measurement was considered. To dissolve the samples, a microwave digestion system was applied to guarantee the total dissolution of the Ca compounds, thus minimizing the sample preparation time, the amounts of reagents used and the risk of contamination. Carbon and Si, normally present in steel samples, were eliminated by treatment with H2SO4 and HF to avoid 12C16O2 and 28Si16O isobaric interferences on the 44Ca isotope. After matrix removal by the use of mercury cathode electrolysis, air–water FI-ICP-MS was used for the determination of Ca. Scandium, with an ionization potential and mass number close to those of Ca, was used as an internal standard for quantitative measurements. The operating parameters for air-water FI-ICP-MS were optimized with respect to signal peak height intensities, stability and matrix effect. The detection limit obtained was 0.6 µg g–1 and the RSD value, calculated from ten replicates of a 200 µl injection of a 50 µg l–1 Ca solution spiked with 2 µg l–1 of Sc, was 0.7%. Data are presented for four certified reference steel materials: JSS 169–5 and 171–5, from Japanese Standards of Iron and Steel; and ECRMs 195–1 (Cr–Ni–steel) and 096 (low-S, low-Ca steel), from the Bureau of Analysed Samples.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Dispersion-Free Solvent Extraction of Cr(VI) from Acidic Solutions Using Hollow Fiber Contactor

Environmental Science & Technology, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Spark Ablation Inductively Coupled Plasma Mass Spectrometry Applied to the Semi-Quantitative Panoramic Analysis of Ferroalloys

Applied Spectroscopy, 2000

The coupling of inductively coupled plasma mass spectrometry (ICP-MS) with spark ablation (SA) wa... more The coupling of inductively coupled plasma mass spectrometry (ICP-MS) with spark ablation (SA) was applied for the semi-quantitative determination of impurities in different types of ferroalloys. The sparking operating conditions were optimized, and a restrictive path including a cyclone and a spray chamber was used to decrease the quantity of sparked material reaching the plasma, to prevent torch injector and sampling cone blockage. Samples were mixed in a 1:2 sample-to-graphite ratio and pressed into pellets for direct solid sampling by the spark. The advantage of the technique includes the benefit of easily determining some refractory elements that are very difficult to dissolve. The method was tested on three different types of ferroalloys: Fe-Ti, Fe-Nb, and Fe-V. A single standard ferroalloy sample was used as an external calibration sample to create a complete response curve for each type of ferroalloy base. Industrial ferroalloys, chemically characterized by using different a...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Use of a Waste-Derived Linde Type-A Immobilized in Agarose for the Remediation of Water Impacted by Coal Acid Mine Drainage at Pilot Scale

Materials

A new adsorbent based on an immobilized waste-derived LTA zeolite in agarose (AG) has proven to b... more A new adsorbent based on an immobilized waste-derived LTA zeolite in agarose (AG) has proven to be an innovative and efficient alternative for removing metallic contaminants from water impacted by acid mine drainage (AMD) because the immobilization prevents the solubilization of the zeolite in acidic media and eases its separation from the adsorbed solution. A pilot device was developed containing slices of the sorbent material [AG (1.5%)–LTA (8%)] to be used in a treatment system under an upward continuous flow. High removals of Fe2+ (93.45%), Mn2+ (91.62%), and Al3+ (96.56%) were achieved, thus transforming river water heavily contaminated by metallic ions into water suitable for non-potable use for these parameters, according to Brazilian and/or FAO standards. Breakthrough curves were constructed and the corresponding maximum adsorption capacities (mg/g) (Fe2+, 17.42; Mn2+, 1.38; Al3+, 15.20) calculated from them. Thomas mathematical model was well fitted to the experimental data...

Bookmarks Related papers MentionsView impact