Cellulose Microfibres Obtained from Agro-Industrial Tara Waste for Dye Adsorption in Water

Microfibres of cellulose were extracted from tara residues (TR), obtained after the production process, and used to remove dyes in aqueous solution. Caesalpinia spinosa (Molina) Kuntze or Tara spinosa, commonly known as tara, is a thorny shrub native to Peru. For these purposes, tara residues (TR) from the production process are used to extract cellulose microfibres (CMF). First, TR are treated in basic mediums; then, they are transferred to an acidic medium. Finally, they are ground in a cutting mill for a short period of time. Scanning electron microscopy was used to characterize CMF. Fibre sizes of approximately 10 µm in length and 300–500 nm in diameter were observed. The crystallinity index calculated from X-ray patterns was defined at 77%. Infrared spectroscopy showed that treating TR with chemical products produces TR delignification. The dye adsorption tests (basic yellow, basic blue 41, basic blue 9 and basic green 4) in water demonstrated that isotherms adjust to the Langmuir model, with maximum respective adsorption values of 43.6, 45.5, 75.0 and 112.2 mg.g-1 for each dye

Identification of rare-earth minerals associated to K-feldspar: Capacsaya project in Peru

A recently discovered the rare-earth-rich site in Capacsaya, located at 123 km northwest of Cusco, at the south of Peru, contains significant quantities of light and heavy rare-earth elements such as neodymium, lanthanum, cerium, europium, and yttrium. This work reports the identification of rare-earth elements and their associated minerals using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analyses. Five (5) samples extracted from different locations at the Capacsaya site were characterized and identified K-feldspar as the mineral associated with the rare-earth elements in a representative sample with a high concentration of lanthanum and cerium. The results showed rare-earth elements contained within the mineral phase monazite, being cerium the dominant element in the phase (La, Ce, Nd)PO4. Finally, through the electrostatic separation process we demonstrate that it was possible to achieve an efficient separation of the K-feldspar phase in the particle size range 75–150 μ m.Fil: Ochoa, J.. Universidad Nacional de Ingeniería; PerúFil: Monteblanco, E.. Commissariat A L Energie Atomique Et Aux Energies Alternatives.; FranciaFil: Cerpa, L.. Instituto Geológico Minero y Metalúrgico; PerúFil: Gutarra Espinoza, Abel. Universidad Nacional de Ingenieria; PerúFil: Aviles Felix, Luis Steven. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; Argentin

Detection of magnetic moment in thin films with a home-made vibrating sample magnetometer

This paper explores the optimization of an array of pick-up coils in a home-made vibrating sample magnetometer for the detection of magnetic moment in thin films. Sensitivity function of a 4-coils Mallinson configuration was numerically studied for the determination of the physical dimensions that enhance the sensitivity of the magnetometer. By performing numerical simulations using the Biot-Savart law combined with the principle of reciprocity we were able to determine the maximum values of sensitivity and the influence of the separation of the coils on the sensitivity function. After the optimization of the pick-up coils, the vibrating sample magnetometer was able to detect the magnetic moment of a 100 nm-thickness Fe19Ni81 magnetic thin film along and perpendicular to the in-plane anisotropy easy axis. The implemented vibrating sample magnetometer is able to detect changes in the magnetic moment of ∼2 × 10-4 emu.Fil: Jordán, D.. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: González Chávez, D.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Laura, D.. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: Leon Hilario, Ludwin Misael. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: Monteblanco, E.. Universite de Lorraine; FranciaFil: Gutarra Espinoza, Abel. Universidad Nacional de Ingeniería. Facultad de Ciencias; PerúFil: Aviles Felix, Luis Steven. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Identification of rare earth minerals associated to K-feldspar: Capacsaya project in Peru

A recently discovered the rare-earth-rich site in Capacsaya, located at 123 km northwest of Cusco, at the south of Peru, contains signifcant quantities of light and heavy rare-earth elements such as neodymium, lanthanum, cerium, europium, and yttrium. This work reports the identifcation of rare-earth elements and their associated minerals using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray difraction analyses. Five (5) samples extracted from diferent locations at the Capacsaya site were characterized and identifed K-feldspar as the mineral associated with the rare-earth elements in a representative sample with a high concentration of lanthanum and cerium. The results showed rare-earth elements contained within the mineral phase monazite, being cerium the dominant element in the phase (La, Ce, Nd)PO4. Finally, through the electrostatic separation process we demonstrate that it was possible to achieve an efcient separation of the K-feldspar phase in the particle size range 75–150 μm

Análisis y diagnóstico térmico en viviendas altoandinas del Perú

El objeto de la investigación que genera este trabajo es diagnosticar la situación térmica actual de cada una de dos viviendas alto andinas del Perú, identificar flujos de calor producidos en ellas y proyectar el mejoramiento térmico correspondiente. Se ha seguido una metodología experimental y analítica apoyada con simulaciones aplicadas a partes específicas de la vivienda. La base de datos experimentales la constituye mediciones y registros automáticos hechos durante 40 a 50 días continuos a partir del 11 de junio de 2008, cuyo procesamiento permite afirmar que las condiciones del ambiente interior de ambas viviendas es severamente frío la mayor parte del día, en el mejor de los casos, se registra 15°C al medio día y -5°C en horas de la madrugada. En aparente contradicción se obtienen potenciales de energía solar ganable por cada vivienda, que podrían ser suficientes para conseguir en ellas las condiciones de confort requeridas, mas paralelamente, se comprueba la existencia de filtraciones de aire elevadas que juegan un papel contrario. En suma, la percepción concluyente es que ambas viviendas requieren de mayor protección contra el enfriamiento que agregados diversos que incrementen su calentamiento.The purpose of the research that stems from this work is to diagnose the current thermal situation of each and every dwelling in the highlands of Peru, to identify heat flows produced inside them and to forecast their thermal improvement. An experimental and analytical methodology has been used, supported by simulations applied to specific parts of the house. The experimental database is constituted by automatic measurements and records taken during 40 to 50 days in a row as from June 11, 2008, and is processing allows to affirm that the conditions of the indoor environment in both houses is severely cold most of the day, being the highest temperatures 15 C at noon and -5 C in the early morning. In apparent contradiction, enough values on net energy entering to the house for thermal comfort were found. But at the same time the existence of elevated air filtrations that play an opposed role is proved. To sum up, the conclusion is that both houses require more protection against cooling instead of diverse mechanisms that increase its warming.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Análisis y diagnóstico térmico en viviendas altoandinas del Perú

El objeto de la investigación que genera este trabajo es diagnosticar la situación térmica actual de cada una de dos viviendas alto andinas del Perú, identificar flujos de calor producidos en ellas y proyectar el mejoramiento térmico correspondiente. Se ha seguido una metodología experimental y analítica apoyada con simulaciones aplicadas a partes específicas de la vivienda. La base de datos experimentales la constituye mediciones y registros automáticos hechos durante 40 a 50 días continuos a partir del 11 de junio de 2008, cuyo procesamiento permite afirmar que las condiciones del ambiente interior de ambas viviendas es severamente frío la mayor parte del día, en el mejor de los casos, se registra 15°C al medio día y -5°C en horas de la madrugada. En aparente contradicción se obtienen potenciales de energía solar ganable por cada vivienda, que podrían ser suficientes para conseguir en ellas las condiciones de confort requeridas, mas paralelamente, se comprueba la existencia de filtraciones de aire elevadas que juegan un papel contrario. En suma, la percepción concluyente es que ambas viviendas requieren de mayor protección contra el enfriamiento que agregados diversos que incrementen su calentamiento.The purpose of the research that stems from this work is to diagnose the current thermal situation of each and every dwelling in the highlands of Peru, to identify heat flows produced inside them and to forecast their thermal improvement. An experimental and analytical methodology has been used, supported by simulations applied to specific parts of the house. The experimental database is constituted by automatic measurements and records taken during 40 to 50 days in a row as from June 11, 2008, and is processing allows to affirm that the conditions of the indoor environment in both houses is severely cold most of the day, being the highest temperatures 15 C at noon and -5 C in the early morning. In apparent contradiction, enough values on net energy entering to the house for thermal comfort were found. But at the same time the existence of elevated air filtrations that play an opposed role is proved. To sum up, the conclusion is that both houses require more protection against cooling instead of diverse mechanisms that increase its warming.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Análisis y diagnóstico térmico en viviendas altoandinas del Perú

El objeto de la investigación que genera este trabajo es diagnosticar la situación térmica actual de cada una de dos viviendas alto andinas del Perú, identificar flujos de calor producidos en ellas y proyectar el mejoramiento térmico correspondiente. Se ha seguido una metodología experimental y analítica apoyada con simulaciones aplicadas a partes específicas de la vivienda. La base de datos experimentales la constituye mediciones y registros automáticos hechos durante 40 a 50 días continuos a partir del 11 de junio de 2008, cuyo procesamiento permite afirmar que las condiciones del ambiente interior de ambas viviendas es severamente frío la mayor parte del día, en el mejor de los casos, se registra 15°C al medio día y -5°C en horas de la madrugada. En aparente contradicción se obtienen potenciales de energía solar ganable por cada vivienda, que podrían ser suficientes para conseguir en ellas las condiciones de confort requeridas, mas paralelamente, se comprueba la existencia de filtraciones de aire elevadas que juegan un papel contrario. En suma, la percepción concluyente es que ambas viviendas requieren de mayor protección contra el enfriamiento que agregados diversos que incrementen su calentamiento.The purpose of the research that stems from this work is to diagnose the current thermal situation of each and every dwelling in the highlands of Peru, to identify heat flows produced inside them and to forecast their thermal improvement. An experimental and analytical methodology has been used, supported by simulations applied to specific parts of the house. The experimental database is constituted by automatic measurements and records taken during 40 to 50 days in a row as from June 11, 2008, and is processing allows to affirm that the conditions of the indoor environment in both houses is severely cold most of the day, being the highest temperatures 15 C at noon and -5 C in the early morning. In apparent contradiction, enough values on net energy entering to the house for thermal comfort were found. But at the same time the existence of elevated air filtrations that play an opposed role is proved. To sum up, the conclusion is that both houses require more protection against cooling instead of diverse mechanisms that increase its warming.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Assessment of cellulose nanofibers from bolaina blanca wood obtained at three shaft heights

This study evaluated cellulose nanofibers from bolaina blanca wood (Guazuma crinita) obtained at different heights of the longitudinal axis of the shaft of trees from a three-and-a-half-year-old plantation. The wood was subjected to pulping, bleaching and subsequent mechanical milling using a Changsha Samy XYQM-2L planetary ball mill to obtain cellulose nanofibers. The product was characterised using analytical techniques: scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy. Additionally, the degree of polymerisation was determined. The effect of longitudinal position on cellulose nanofibers characteristics was evaluated by comparing means using ANOVA and Kruskal–Wallis statistical tests. The yield of cellulose nanofibers production from the high, middle and basal sections was 32,1 %, 33,6 % and 31 %, respectively. The obtained cellulose nanofibers exhibited a significantly larger diameter for the high zone (84 nm) compared with the middle (75 nm) and basal (69 nm) zones; the length remained above the micrometre range. With respect to degree of polymerisation, a decrease was evidenced with respect to the increase in shaft height; the basal zone exhibited a degree of polymerisation of 300, a significantly higher value than the middle and high zones, which exhibited degree of polymerisation of 249 and 211, respectively. The product showed typical cellulose type I polymorphism and crystallinity indexes of 76 %, 93 % and 96 % for the high, middle and basal sections, respectively. Regarding the thermostability of cellulose nanofibers, the maximum degradation rate of cellulose nanofibers occurred between 335 °C and 341 °C, with cellulose nanofibers from the basal area being the most stable. The adsorption of the methylene blue dye on cellulose nanofibers was evaluated; an efficiency > 60 % was found

Evaluación experimental de cambios constructivos para lograr confort térmico en una vivienda altoandina del Perú

El presente artículo reporta el trabajo realizado en una vivienda de una comunidad rural altoandina peruana y las acciones llevadas a cabo para brindar alternativas de solución a la problemática que genera el frío intenso (friaje) dentro de la vivienda. Se midieron desde junio del 2008 y por un periodo de 14 meses las condiciones climáticas en la comunidad rural (3700 m.s.n.m.). Así también se registraron temperaturas de aire y humedad relativa (H.R.) en los ambientes de la vivienda seleccionada de dicha comunidad; midiéndose además, temperaturas superficiales en: paredes, suelo, techos, ventanas, etc. Se hicieron modelos de simulación térmica de la vivienda usando el software de simulación térmica en edificios: EnergyPlus 3.0; obteniéndose la propuesta de modificación constructiva más adecuada para lograr incrementar la temperatura dentro de la vivienda. Se realizaron las modificaciones constructivas seleccionadas y nuevamente se monitoreó las condiciones térmicas al interior y exterior de la vivienda modificada.The present article reports work made on a dwelling from a Peruvian highland rural community, detailing means activities developed with the goal of finding solution alternatives to the problematic generated for the intense cold (friaje) inside the dwelling. It was measured since June 2008 and for a 14 months period the climatic conditions in the rural community (3700 m.s.n.m.). It was also measured the air temperature and relative humidity (R.H.) in the selected dwelling rooms of the mentioned community; it was measured superficial temperatures in: walls, ground, ceilings, windows, etc. Some thermal simulation models of the dwelling were developed; for this, it was used the building thermal simulation software: EnergyPlus 3.0; it was obtained the most adequate constructive modification propose for reaching temperature increase inside the dwelling. Constructive selected modifications were made, after that interior and exterior thermal conditions were registered once again.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Evaluación experimental de cambios constructivos para lograr confort térmico en una vivienda altoandina del Perú

El presente artículo reporta el trabajo realizado en una vivienda de una comunidad rural altoandina peruana y las acciones llevadas a cabo para brindar alternativas de solución a la problemática que genera el frío intenso (friaje) dentro de la vivienda. Se midieron desde junio del 2008 y por un periodo de 14 meses las condiciones climáticas en la comunidad rural (3700 m.s.n.m.). Así también se registraron temperaturas de aire y humedad relativa (H.R.) en los ambientes de la vivienda seleccionada de dicha comunidad; midiéndose además, temperaturas superficiales en: paredes, suelo, techos, ventanas, etc. Se hicieron modelos de simulación térmica de la vivienda usando el software de simulación térmica en edificios: EnergyPlus 3.0; obteniéndose la propuesta de modificación constructiva más adecuada para lograr incrementar la temperatura dentro de la vivienda. Se realizaron las modificaciones constructivas seleccionadas y nuevamente se monitoreó las condiciones térmicas al interior y exterior de la vivienda modificada.The present article reports work made on a dwelling from a Peruvian highland rural community, detailing means activities developed with the goal of finding solution alternatives to the problematic generated for the intense cold (friaje) inside the dwelling. It was measured since June 2008 and for a 14 months period the climatic conditions in the rural community (3700 m.s.n.m.). It was also measured the air temperature and relative humidity (R.H.) in the selected dwelling rooms of the mentioned community; it was measured superficial temperatures in: walls, ground, ceilings, windows, etc. Some thermal simulation models of the dwelling were developed; for this, it was used the building thermal simulation software: EnergyPlus 3.0; it was obtained the most adequate constructive modification propose for reaching temperature increase inside the dwelling. Constructive selected modifications were made, after that interior and exterior thermal conditions were registered once again.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES