32 research outputs found
Nitrogen dopedTiO2 photoactive in visible light
In this research TiO2 modified with nitrogen has been prepared. The synthesis method used was sol gel from the hydrolysis of titanium tetrabutoxide with urea solution, combined with a low temperature treatment at atmospheric pressure. The theoretical mole ratio N/Ti was equal to 0.5 and the theoretical mole ratio HNO3/TiO2 was equal to 0.5. The solid obtained was calcined at different temperatures in static air with high heating rate and residence time of 1 hour. The samples were characterized by X-ray diffraction, FTIR Raman and diffuse reflectance spectroscopy, thermodifferential and thermogravimetric analysis and specific surface area. All calcined solids exhibit absorption in the visible range. The Raman spectroscopy and X-ray diffraction revealed for all the heat treatments, the presence of crystalline phases corresponding to anatase and brookite polymorphism. The photocatalytic activity of the catalysts was tested in degradation of an artificial dye under visible light, yielding the best results for the sample treated at 250°C. Our results allow to say that this behaviour is due to the absorption of visible light, good efficiency for the adsorption of the dye and presence of two crystalline phases that decreases the recombination of photogenerated electrons and holes. The synthesis technique used allows obtaining solids with textural and attractive photocatalytic properties.Fil: Pérez, Eliana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones Para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones Para la Industria Química; ArgentinaFil: Vittorio, Luca. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones Para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones Para la Industria Química; ArgentinaFil: Sham, Edgardo Ling. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones Para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones Para la Industria Química; Argentin
Síntesis de TiO2: Efecto de las variables de síntesis en la actividad fotocatalítica
Las propiedades fotocatalíticas del óxido de titanio sintetizado por la técnica sol-gel, fueron evaluadas en la reacción fotoasistida de degradación de un colorante artificial (tartrazina). Se estudió el efecto del orden de agregado de los reactivos en la síntesis: 1_ medio hidrolizante acidulado con ac. 4- hidroxibenzoico sobre el precursor de Ti y 2_ precursor de Ti sobre el medio hidrolizante acidulado con ac. 4-hidroxibenzoico . Los sólidos fueron calcinados a 300, 500 y 700 ºC. y fueron caracterizadas por análisis térmico diferencial, difracción de rayos X y microscopía electrónica. El estudio de la influencia del orden de agregado de los reactivos y el tratamiento térmico sobre el comportamiento catalítico de los sólidos obtenidos, muestra que la mejor actividad catalítica se obtiene agregando el medio hidrolizante acidulado sobre el precursor y calcinando a 500 ºC. La explicación para esta reactividad puede atribuirse a las especies formadas inicialmente, que influyen en las reacciones de policondensación secundarias, que a su vez afectan la morfología y la estructura cristalina de los sólidos resultantes.The photocatalytic properties of titanium oxide synthesized by sol - gel, were evaluated in the photo assisted reaction of an artificial dye’s (tartrazine) degradation. The reagent’s order of addition effect in the synthesis was studied: 1_ hydrolyzing medium on precursor and 2_ precursor on the hydrolyzing medium. Solids were calcined at 300, 500 and 700 °C and were characterized by differential thermal analysis, X-ray diffraction and electronic microscopy. The study on the influence of reagent’s order of addition and thermal treatment on the catalytic behavior of the solid, show that the best catalytic activity is obtained by adding the hydrolyzing medium on the precursor and calcining at 500 ° C. The explanation to this reactivity can be attributed to the species formed initially which have an influence on the secondary polycondensation reactions, which in turn affect morphology and the crystal structure of the resulting solids.Fil: Cornejo, Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ingeniería; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Exactas; ArgentinaFil: Sham, Edgardo Ling. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ingeniería; Argentin
Photodegradation of herbicide Metsulfuron-methyl with TiO2 supported on magnetite particles coated with SiO2
Natural watercourses may be significantly contaminated due to the increase of agricultural activities, making it necessary to develop new methodologies for the remediation of agrochemicals, including herbicides. To this effect, photodegradation with TiO2 is a very effective process. However, this semiconductor cannot be easily removed from the treated aqueous medium. Supporting the photocatalyst on different materials facilitates its removal by several methods, including magnetic attraction. According to this goal, this work reports the synthesis of TiO2 photocatalysts supported on SiO2-coated magnetite particles (Fe3O4) by a lowerature sol-gel process (75†°C). By varying the aging time of the TiO2 sol, materials with different structural properties and combinations of anatase-brookite phases were obtained. Of all the synthesized solids, the one with the highest photocatalytic activity in the degradation of model compounds was the TiO2/SiO2/Fe3O4 catalyst with a 47.4/13.6/39.0†wt % respectively. Under optimal working conditions and at a pH value close to neutrality (conditions in which Metsulfuron-methyl is persistent in an aqueous medium) this catalyst degraded 70% of the herbicide initial concentration in three and a half hours of artificial irradiation with an activity similar to the mass TiO2. The aging time significantly influenced on structural properties of supported TiO2. With its increase, the degree of crystallinity of the samples also increased but its specific surface decreased. The catalyst with higher photoactivity blends the best combination of both factors and is, therefore, a good alternative for the remediation of contaminated effluents with commercial formulations of this herbicide. Also, its magnetic support facilitates its subsequent removal from treated water samples.Fil: Montañez, Juan Paulo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Heredia, Carla Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Sham, Edgardo Ling. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin
Síntesis, Caracterización y Actividad fotocatalítica de TiO2 depositada sobre SiO2 - Fe3O4
El TiO2 en fase anatasa obtenido mediante la técnica sol-gel, a baja temperatura se deposita sobre un sistema de óxidos conformados por núcleos magnéticos de Fe3O4 encapsulados en una red de SiO2 mesoporosa, los cuales se incorporan mediante un surfactante catiónico, bromuro de cetiltrimetilamonio (CTAB), en la síntesis. Para favorecer la formación de la estructura mesoporosa, el CTAB es eliminado posteriormente por calcinación a 350 °C. Se estudiaron diferentes relaciones molares [CTAB]/[Si]. Los sólidos se caracterizaron mediante DRX y superficie específica de BET. La actividad fotocatalítica de los catalizadores fue evaluada en la degradación del colorante azoico artificial tartrazina, y también se analizó la efectividad de cada catalizador por unidad de masa, lo que comúnmente se conoce como turnover rate, determinándose de ese modo el mejor rendimiento fotocatalítico. Los resultados obtenidos indicaron que la deposición de la titania en sílice mesoporosa produce un catalizador con mayor actividad fotocatalítica.TiO2 anatase phase was obtained at low temperature by the sol-gel technique. TiO2 has been deposited on a system of oxides made up of magnetic nuclei of Fe3O4 encapsulated by a mesoporous SiO2 network, which have been achieved from the incorporation in the synthesis by a cationic surfactant cetyltrimethylammonium bromide (CTAB). To promote the formation of the mesoporous structure, the CTAB was subsequently removed by calcination at 350 ° C. Different molar ratios [CTAB] / [Si] have been studied. The solids were characterized by XRD and specific surface BET. The photocatalytic activity of the catalysts was evaluated in the degradation of the artificial azo dye tartrazine, and the specific effectiveness of each catalyst was also analyzed, through turnover rate, thus obtaining the best photocatalytic performance. The observed results indicated that the deposition of titania on mesoporous silica results in a catalyst with improved photocatalytic activity.Fil: Heredia, Carla Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Exactas; ArgentinaFil: Sham, Edgardo Ling. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ingeniería; Argentin
Identification and quantification of the interaction mechanisms between the cationic surfactant HDTMA-Br and montmorillonite
Using a montmorillonite and the cationic surfactant hexadecyltrimethylammonium bromide (HDTMABr), a series of organoclays were synthesized with progressively increasing surfactant loads of between 0.2 and 4.0 times the cation exchange capacity of the starting clay. Different experimental techniques were used (thermal techniques, XPS, zeta potential) for characterizing the solids. The results obtained allowed to distinguish between the fraction of surfactant adsorbed by strong interactions and the fraction adsorbed by weak interactions. Adsorption isotherms of each of these processes were constructed, and were then adjusted using the Langmuir and Dubinin-Radusquevich adsorption models. Three types of interaction between the surfactant and the clay were identified and described, qualitatively and quantitatively. Two of these interactions, strong and weak, involve the hexadecyltrimethylammonium cation (HDTMA+). The third is a weak interaction involving the ion pair HDTMA+Br-.Fil: Naranjo, Pablo Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); ArgentinaFil: Sham, Edgardo Ling. Universidad Nacional de Salta. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación para la Industria Química (i); ArgentinaFil: Rodriguez Castellón, Enrique. Universidad de Malaga; EspañaFil: Torres Sanchez, Rosa Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro Tecnológico de Recursos Minerales y Cerámica (i); ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); Argentina. Universidad Nacional de Salta. Facultad de Ciencias Exactas; Argentin
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Chronic Arsenic Toxicity: Statistical Study of the Relationships Between Urinary Arsenic, Selenium and Antimony
Background: The groundwater of Argentina’s Chaco plain presents arsenic levels above those suitable for human consumption. Studies suggest skin disorders among local populations caused by arsenic intake. The relationship between urinary arsenic and arsenic in drinking water is well known, but urinary arsenic alone is not enough for risk assessment due to modulating factors such as the intake of selenium and antimony. Objectives: Determining the relationship between urinary arsenic, selenium and antimony could contribute to the study of arsenic metabolization in humans. Methods: Arsenic, selenium and antimony, relative to urinary creatinine, was quantified in urine samples to assess exposure to arsenic and its toxicity modulators. Results: Arsenic levels were higher than reference value in 89% of exposed group. Selenium concentrations were higher in 84%. Levels of antimony were also surprisingly high, not compatible with dietary intake. Urinary arsenic and selenium data showed highly significant correlations with age. Adult females presented higher urinary arsenic values than adult males. Conclusions: Values related to urinary creatinine were much higher than values considered normal. Concentrations of arsenic and selenium diminished with age for children and increased for adults. Women showed higher concentrations than men. Positive correlation was found between arsenic and selenium. No correlation was seen between urinary antimony, arsenic nor selenium.Fil: Boemo, Analía. Universidad Nacional de Salta. Facultad de Ciencias Exactas; Argentina. Universidad Nacional de Salta. Consejo de Investigación; ArgentinaFil: Lomniczi, Irene Maria. Universidad Nacional de Salta. Facultad de Ciencias Exactas; Argentina. Universidad Nacional de Salta. Consejo de Investigación; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin
Characterization of hexadecyltrimethylammonium-organoclay and its individual components by thermal techniques
The properties of the materials determine their potential applications. The aim of this article is to study the properties of the organoclays using simple and rapid technologies. Organoclays with different surfactant loadings (SL) were synthesized using an Argentine bentonite with a high content of montmorillonite (Bent) and hexadecyltrimethylammonium bromide as cationic surfactant. The samples were characterized using thermal techniques. The results revealed that the hydrophilicity of the organoclays decreases with increasing SL until the SL reaches 0.8 times the cation exchange capacity of the clay; and remains constant at a higher surfactant load. The stability of organoclays was inversely proportional to the SL of each sample. The layers showed a stabilization of approximately 40°C for their structural transformation temperature, caused by the presence of the surfactant. In addition, at a SL 1.0 the structure was ‘solid-like’.Fil: Naranjo, Pablo Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Sham, Edgardo Ling. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin
Degradación fotocatalitica de compuestos orgánicos utilizando titania modificada activa bajo luz visible
Titania (TiO2) se sintetizó por el método sol-gel, mediante la hidrólisis de isopropóxido de titanio con agua, empleando ciclohexano como medio dispersante. La titania se modificó con iones de Cr6+, con concentraciones de 0,5; 1,0; 1,5% m/m de Cr. Los materiales se trataron térmicamente a 400°C y se caracterizaron por Reflectancia Difusa (DRS), Espectroscopia Raman, Análisis termogravimétrico (TG) y termodiferencial (ATD) y Superficie Específica. La actividad fotocatalítica fue determinada mediante el estudio de la degradación de un colorante azoico (amarillo 5) y de un compuesto orgánico aromático pdihidroxibenceno (quinol), bajo radiación de luz visible. Para ambos compuestos orgánicos se observa una mayor actividad fotocatalítica en los sólidos dopados.TiO2 was synthesized by the sol-gel method, by hydrolysis of titanium isoproxide with water, using cyclohexane as the dispersing medium. The titania was modified with Cr6 + ions, with concentrations of 0.5; 1.0; 1.5% m/m Cr. The materials were thermally treated at 400 °C and characterized by Diffuse Reflectance (DRS), Raman Spectroscopy, Thermogravimetric (TG) and Thermodifferential Analysis (ATD), and Specific Surface. The photocatalytic activity was determined by studying the degradation of an azo dye (yellow 5) and aromatic organic compound p-dihidroxybencene (hydroquinone) under visible light radiation. For both organic compounds, a higher photocatalitic activity is observed in doped solids.Fil: Cardozo, Ana Elizabeth. Universidad Nacional de Salta. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Farfan Torres, Elsa Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Exactas; ArgentinaFil: Sham, Edgardo Ling. Universidad Nacional de Salta. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin