DISEÑO DE UNA COLUMNA DE ABSORCIÓN EMPACADA CONSIDERANDO CUATRO TIPOS DE EMPAQUE Y APLICANDO MATLAB

In the present work, a packed bed absorption column is designed to recover certain amounts of ethanol contained in a gaseous stream. Four packing types (50-mm metal Hiflow® rings, 50-mm ceramic Pall® rings, 50-mm metal Top Pak® rings and 25-mm metal VSP® rings) are considered in order to select the most appropriate one in terms of column dimensions, pressure drop and mass-transfer results. Several design parameters were determined including column diameter (D), packing height (Z), overall mass-transfer coefficient (Km) and gas pressure drop (P/Z), as well as the overall number of gas-phase transfer units (NtOG), overall height of a gas-phase transfer unit (HtOG) and the effective surface area of packing (ah). The most adequate packing to use for this absorption system constitutes the 25-mm metal VSP® rings, since it provided the greatest values of Km (0.325 kmol/m3.s), and ah (169.57 m-1), as well as the lowest values of both Z (0.6 m) and HtOG (0.145 m), meaning that it will supply the higher mass-transfer conditions with the lowest column dimensions. The influence of both gas mixture (QG) and solvent (mL) feed flowrates on D, Z, Km, P/Z, NtOG and HtOG was also evaluated for the four packing considered. The design methodology was solved using computing software MATLAB® version 7.8.0.347 (R2009a) (Math Works, 2009), and also Microsoft Excel®.DEn el presente trabajo se diseña una columna de absorción empacada para recuperar ciertas cantidades de etanol contenido en una corriente gaseosa. Se consideran 4 tipos de empaques (anillos Hiflow® metálicos de 50 mm, anillos Pall® cerámicos de 50 mm, anillos Top Pak® metálicos de 50 mm, y anillos VSP® metálicos de 25 mm) con el fin de seleccionar el más apropiado en términos de dimensiones de la columna, caída de presión y resultados de transferencia de masa. Se determinaron varios parámetros de diseño incluyendo diámetro de la columna (D), altura del empaque (Z), coeficiente global de transferencia de masa (Km) y caída de presión gaseosa (P/Z), así como también el número total de unidades de transferencia den fase gaseosa (NtOG), altura total de unidades de transferencia en fase gaseosa (HtOG) y el área superficial efectiva del empaque (ah). El empaque más adecuado de usar en este sistema de absorción constituye los anillos VSP® metálicos de 25 mm, ya que suministra los mayores valores de Km (0.325 kmol/m3.s), y ah (169.57 m-1), así como también los menores valores de tanto Z (0.6 m) y HtOG (0.145 m), significando que suministrará las condiciones más altas de transferencia de masa con las menores dimensiones dela columna. La influencia de los caudales de alimentación de tanto la mezcla gaseosa (QG) y el solvente (mL) sobre D, Z, Km, DP/Z, NtOG y HtOG fue también evaluada para los cuatro tipos de empaques considerados. La metodología de diseño fue resuelta empleando el software MATLAB® versión 7.8.0.347 (R2009a) (Math Works, 2009), y también Microsoft Excel®

DISEÑO DE UNA COLUMNA DE ABSORCIÓN EMPACADA CONSIDERANDO CUATRO TIPOS DE EMPAQUE Y APLICANDO MATLAB

In the present work, a packed bed absorption column is designed to recover certain amounts of ethanol contained in a gaseous stream. Four packing types (50-mm metal Hiflow® rings, 50-mm ceramic Pall® rings, 50-mm metal Top Pak® rings and 25-mm metal VSP® rings) are considered in order to select the most appropriate one in terms of column dimensions, pressure drop and mass-transfer results. Several design parameters were determined including column diameter (D), packing height (Z), overall mass-transfer coefficient (Km) and gas pressure drop (P/Z), as well as the overall number of gas-phase transfer units (NtOG), overall height of a gas-phase transfer unit (HtOG) and the effective surface area of packing (ah). The most adequate packing to use for this absorption system constitutes the 25-mm metal VSP® rings, since it provided the greatest values of Km (0.325 kmol/m3.s), and ah (169.57 m-1), as well as the lowest values of both Z (0.6 m) and HtOG (0.145 m), meaning that it will supply the higher mass-transfer conditions with the lowest column dimensions. The influence of both gas mixture (QG) and solvent (mL) feed flowrates on D, Z, Km, P/Z, NtOG and HtOG was also evaluated for the four packing considered. The design methodology was solved using computing software MATLAB® version 7.8.0.347 (R2009a) (Math Works, 2009), and also Microsoft Excel®.DEn el presente trabajo se diseña una columna de absorción empacada para recuperar ciertas cantidades de etanol contenido en una corriente gaseosa. Se consideran 4 tipos de empaques (anillos Hiflow® metálicos de 50 mm, anillos Pall® cerámicos de 50 mm, anillos Top Pak® metálicos de 50 mm, y anillos VSP® metálicos de 25 mm) con el fin de seleccionar el más apropiado en términos de dimensiones de la columna, caída de presión y resultados de transferencia de masa. Se determinaron varios parámetros de diseño incluyendo diámetro de la columna (D), altura del empaque (Z), coeficiente global de transferencia de masa (Km) y caída de presión gaseosa (P/Z), así como también el número total de unidades de transferencia den fase gaseosa (NtOG), altura total de unidades de transferencia en fase gaseosa (HtOG) y el área superficial efectiva del empaque (ah). El empaque más adecuado de usar en este sistema de absorción constituye los anillos VSP® metálicos de 25 mm, ya que suministra los mayores valores de Km (0.325 kmol/m3.s), y ah (169.57 m-1), así como también los menores valores de tanto Z (0.6 m) y HtOG (0.145 m), significando que suministrará las condiciones más altas de transferencia de masa con las menores dimensiones dela columna. La influencia de los caudales de alimentación de tanto la mezcla gaseosa (QG) y el solvente (mL) sobre D, Z, Km, DP/Z, NtOG y HtOG fue también evaluada para los cuatro tipos de empaques considerados. La metodología de diseño fue resuelta empleando el software MATLAB® versión 7.8.0.347 (R2009a) (Math Works, 2009), y también Microsoft Excel®

Escenario en la precordillera

35 p.Escuela de Arquitectura, Universidad de Talca.Resumen de ObraAlumno: Período: 2009-2010.Proceso Diseño: Marzo 2009 - Noviembre 2009.Proceso de Construcción: Diciembre 2009 - Enero 2011.Comisión Evaluadora: German Valenzuela, Kenneth Gleiser, Fernando MontoyaProfesor Guía: Juan Roman PerezUbicación: Escuela La Cordillera de Los Lleuques, Los Lleuques, Comuna de Pinto VIII RegiónParticipantes Construcción: Trabajadores de Proyectos Municipales, con Fondos Casino. Financiamiento: Ilustre Municipalidad de PintoCosto de la obra: $ 3.720.378

Combined Experimental and Molecular Simulation Study of Insulin-Chitosan Complexation Driven by Electrostatic Interactions

Protein−polysaccharide complexes constructed via self-assembly methods are often used to develop novel 17 biomaterials for a wide range of applications in biomedicine, food, and biotechnology. The objective of this work was to 18 investigate theoretically and to demonstrate via constant-pH Monte Carlo simulations that the complexation phenomenon 19 between insulin (INS) and the cationic polyelectrolyte chitosan (CS) is mainly driven by an electrostatic mechanism. 20 Experimental results obtained from FTIR spectra and ζ-potential determinations allowed us to complement the conclusions. 21 The characteristic absorption bands for the complexes could be assigned to a combination of signals from CS amide I and INS 22 amide II. The second peak corresponds to the interaction between the polymer and the protein at the level of amide II. INS− 23 CS complexation processes not expected when INS is in its monomeric form, but for both tetrameric and hexameric forms, 24 incipient complexation due to charge regulation mechanism took place at pH 5. The complexation range was observed to be 5.5 25 < pH < 6.5. In general, when the number of INS units increases in the simulation process, the solution pH at which the 26 complexation can occur shifts toward acidic conditions. CS’s chain interacts more efficiently, i.e. in a wider pH range, with INS 27 aggregates formed by the highest monomer number. The charge regulation mechanism can be considered as a previous phase 28 toward complexation (incipient complexation) caused by weak interactions of a Coulombic nature.Fil: Prudkin Silva, Cecilia Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Pérez, Carlos E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Martínez, Karina Dafne. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Barroso da silva, Fernando. Universidade do Sao Paulo. Departamento de Bioquímica; Brasi

Histopathological lesions in central nervous system of goats poisoned by Ipomoea carnea

Ipomoea carnea var. fistulosa (Convolvulaceae) is a perenne poisonous plant, found throughout the Argentine Northeastern. The intoxication produces a lysosomal storage disease in goats, sheep and cattle. Five goats were fed with 50 g/kgBW/day of fresh leaves, flowers and stems of I. carnea, during 43–60 days. Hirsute coat, depression, difficulty to stand up, ataxia, hypermetria, wide–based stance, incoordination of muscular movements, intense tremors, spastic paresis, abnormal postural reactions, nystagmus, hyperreflexia, hypersensitivity to sound, head tilting and loss of equilibrium were observed in all treated animals. The histopathologic study revealed the presence of cytoplasmatic vacuolation mainly in medulla oblongata and cerebellum. Control animals did not show any alterations. We conclude that this poisoning causes central nervous system damage, being Purkinje cells the most severely affected

Combined Experimental and Molecular Simulation Study of Insulin-Chitosan Complexation Driven by Electrostatic Interactions

Protein−polysaccharide complexes constructed via self-assembly methods are often used to develop novel 17 biomaterials for a wide range of applications in biomedicine, food, and biotechnology. The objective of this work was to 18 investigate theoretically and to demonstrate via constant-pH Monte Carlo simulations that the complexation phenomenon 19 between insulin (INS) and the cationic polyelectrolyte chitosan (CS) is mainly driven by an electrostatic mechanism. 20 Experimental results obtained from FTIR spectra and ζ-potential determinations allowed us to complement the conclusions. 21 The characteristic absorption bands for the complexes could be assigned to a combination of signals from CS amide I and INS 22 amide II. The second peak corresponds to the interaction between the polymer and the protein at the level of amide II. INS− 23 CS complexation processes not expected when INS is in its monomeric form, but for both tetrameric and hexameric forms, 24 incipient complexation due to charge regulation mechanism took place at pH 5. The complexation range was observed to be 5.5 25 < pH < 6.5. In general, when the number of INS units increases in the simulation process, the solution pH at which the 26 complexation can occur shifts toward acidic conditions. CS’s chain interacts more efficiently, i.e. in a wider pH range, with INS 27 aggregates formed by the highest monomer number. The charge regulation mechanism can be considered as a previous phase 28 toward complexation (incipient complexation) caused by weak interactions of a Coulombic nature.Fil: Prudkin Silva, Cecilia Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Pérez, Carlos E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Martínez, Karina Dafne. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Barroso da silva, Fernando. Universidade do Sao Paulo. Departamento de Bioquímica; Brasi

Validating Regulatory Sensory Processing Disorders Using the Sensory Profile and Child Behavior Checklist (CBCL 1 –5)

The objective was to validate Regulatory Sensory Processing Disorders’ criteria (DC:0-3R, 2005) using empirical data on the presence and severity of sensory modulation deficits and specific psychiatric symptoms in clinical samples. Sixty toddlers who attended a child mental health unit were diagnosed by a clinical team. The following two groups were created: toddlers with RSPD(N = 14) and those with ‘‘other diagnoses in Axis I/II of the DC:0-3R00(OD3R) (N = 46). Independently of the clinical process, parents completed the Infant Toddler Sensory Profile (as a checklist for sensory symptoms) and the Achenbach Behavior Checklist for ages 1/2–5 (CBCL 1/2–5). The scores from the two groups were compared. The results showed the following for the RSPD group: a higher number of affected sensory areas and patterns than in the OD3R group; a higher percentage of sensory deficits in specific sensory categories; and a higher severity of behavioral symptoms such as withdrawal, inattention, other externalizing problems and pervasive developmental problems in CBCL 1/2–5. The results confirmed our hypotheses by indicating a higher severity of sensory symptoms and identifying specific behavioral problems in children with RSPD. The results revealed convergent validity between the instruments and the diagnostic criteria for RSPD and supported the validity of RSPD as a unique diagnosis. The findings also suggested the importance of identifying sensory modulation deficits in order to develop an early intervention to enhance the sensory capacities of children who do not fully satisfy the criteria for some DSM-IV-TR disorders

The Role of Sensory Modulation Deficits and Behavioral Symptoms in a Diagnosis for Early Childhood

To contribute to the validation of the sensory and behavioral criteria for Regulation Disorders of Sensory Processing (RDSP) (DC:0-3R, 2005), this study examined a sample of toddlers in a clinical setting to analyze: (1) the severity of sensory modulation deficits and the behavioral symptoms of RDSP; (2) the associations between sensory and behavioral symptoms; and (3) the specific role of sensory modulation deficits in an RDSP diagnosis. Based on clinical observations, 78 toddlers were classified into two groups: toddlers with RDSP (N = 18) and those with‘‘other diagnoses in Axis I/II of the DC:0-3R’’ (OD3R; N = 60). The parents completed the Infant Toddler Sensory Profile and the Achenbach Checklist. The results revealed that the RDSP group had more severe sensory modulation deficits and specific behavioral symptoms; stronger, although not significant, associations between most sensory and behavioral symptoms; and a significant sensory modulation deficit effect. These findings support the validity of RDSP

O ensino como trabalho – o professor como trabalhador

Dans cet article, à partir d’une nouvelle perspective - ancrée sur la distinction travail prescrit/travail réel, établie par l’ergomie de l’activité et son articulation à la notion de gendre professionnel, préconisée par Faït & Clot - est proposée une contribution au développement des recherches sur l’ interaction professeur étudiant