The distribution in a territory of centers of economic activity, such as supermarkets, obey an area of influence that covers a defined population. This distribution can be explained by geographic spatial models that analyze their location and interrelations between economic cores. One of these models is the Central Place Theory (CPT), proposed by Christaller in 1933. In Ecuador, the main company of service and commercialization of products of first necessity is Corporacion Favorita, which has Supermaxi and Megamaxi supermarkets located in several cities of the country. Quito, Guayaquil and Cuenca, for their extension and importance for the economy of the country were chosen for the study. Using a GIS, the CPT was applied with different coverage centers (range 1, 2, 3, and 4), and the model was adjusted to the location of the supermarkets. In Cuenca and Guayaquil, the model correctly explained the spatial distribution of the supermarkets, while in Quito the model demonstrated to a large extent the spatialization in the north, south of the city, however, in the northern center and in the valleys of the city did not represent the spatial dynamics. The economic geography, through the CPT explained the spatial distribution of supermarkets, and presents a technical tool in the decision making for businessmen and the territorial ordering of a city.
{"title":"Aplicación del modelo de Christaller para la distribución espacial de supermercados","authors":"I. F. Palacios-Orejuela","doi":"10.18537/MSKN.09.02.02","DOIUrl":"https://doi.org/10.18537/MSKN.09.02.02","url":null,"abstract":"The distribution in a territory of centers of economic activity, such as supermarkets, obey an area of influence that covers a defined population. This distribution can be explained by geographic spatial models that analyze their location and interrelations between economic cores. One of these models is the Central Place Theory (CPT), proposed by Christaller in 1933. In Ecuador, the main company of service and commercialization of products of first necessity is Corporacion Favorita, which has Supermaxi and Megamaxi supermarkets located in several cities of the country. Quito, Guayaquil and Cuenca, for their extension and importance for the economy of the country were chosen for the study. Using a GIS, the CPT was applied with different coverage centers (range 1, 2, 3, and 4), and the model was adjusted to the location of the supermarkets. In Cuenca and Guayaquil, the model correctly explained the spatial distribution of the supermarkets, while in Quito the model demonstrated to a large extent the spatialization in the north, south of the city, however, in the northern center and in the valleys of the city did not represent the spatial dynamics. The economic geography, through the CPT explained the spatial distribution of supermarkets, and presents a technical tool in the decision making for businessmen and the territorial ordering of a city.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42986313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ochoa‐Sánchez, L. Timbe, Angel Vázquez‐Patiño, E. Samaniego
Floods represent a severe cause of deaths and economic loss. In order to prevent, mitigate, and reduce flood risks and their consequences, hydraulic models allow analysing and mapping floods. The results of an appropriate model that works under local conditions are a valuable tool for local governments leading to sustainable management of floodplains. Around the world, high-mountain rivers have been poorly modelled; their orography and data scarcity present an extra research difficulty. Considering that all one-dimensional models assume that the river bed slope is small, this study evaluated two widely applied one-dimensional models: Mike11 and HEC-RAS, for modelling a high mountain river. Their best configuration under complex topographical conditions and their potential use was assessed by calibration and validation of the models. We found that the HEC-RAS model was not able to define a stable solution of the hydrodynamic modelling of the river, while Mike11 yielded stable results. Furthermore, the validation of the Mike11 model showed good performance. This study sets a precedent in the 1D modelling of high-mountain rivers with data scarcity.
{"title":"Unidimensional, non-stationary modeling of a high mountain river in southern Ecuador","authors":"A. Ochoa‐Sánchez, L. Timbe, Angel Vázquez‐Patiño, E. Samaniego","doi":"10.18537/MSKN.09.02.08","DOIUrl":"https://doi.org/10.18537/MSKN.09.02.08","url":null,"abstract":"Floods represent a severe cause of deaths and economic loss. In order to prevent, mitigate, and reduce flood risks and their consequences, hydraulic models allow analysing and mapping floods. The results of an appropriate model that works under local conditions are a valuable tool for local governments leading to sustainable management of floodplains. Around the world, high-mountain rivers have been poorly modelled; their orography and data scarcity present an extra research difficulty. Considering that all one-dimensional models assume that the river bed slope is small, this study evaluated two widely applied one-dimensional models: Mike11 and HEC-RAS, for modelling a high mountain river. Their best configuration under complex topographical conditions and their potential use was assessed by calibration and validation of the models. We found that the HEC-RAS model was not able to define a stable solution of the hydrodynamic modelling of the river, while Mike11 yielded stable results. Furthermore, the validation of the Mike11 model showed good performance. This study sets a precedent in the 1D modelling of high-mountain rivers with data scarcity.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43364970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Pérez, J. Quishpi, Guillermina Pauta, Fabian Leon, Juan F. Cisneros, Verónica Pinos, Andres Alvarado
The lipids of microalgae are the source for obtaining third-generation biofuels so that fossil fuels can be replaced. The objectives of this study were to determine the composition of the lipids of Chlorella and Scenedesmus microalgae using the gravimetric method; Determine the efficiency of different solvents for the extraction of lipids with the Soxhlet method and compare the lipid recovery productivities of Chlorella microalgae with thermal and physical pretreatments. The highest amount of lipids, 20.37% per dry sample, the microalga, the chlorella, the solvent mixture, the chloroform:methanol in a 1:2 ratio. The increase in the amount of lipids generated with the use of pretreatments no justifies its use for which it is recommended that no pretreatment be applied. The results allow to establish a baseline in the use of microalgae cultivable in the Ecuadorian mountain to obtain lipids for biofuels.
{"title":"Comparación de las eficiencias de recuperación de lípidos de las microalgas Chlorella y Scenedesmus obtenidas con diferentes disolventes","authors":"M. Pérez, J. Quishpi, Guillermina Pauta, Fabian Leon, Juan F. Cisneros, Verónica Pinos, Andres Alvarado","doi":"10.18537/MSKN.09.02.04","DOIUrl":"https://doi.org/10.18537/MSKN.09.02.04","url":null,"abstract":"The lipids of microalgae are the source for obtaining third-generation biofuels so that fossil fuels can be replaced. The objectives of this study were to determine the composition of the lipids of Chlorella and Scenedesmus microalgae using the gravimetric method; Determine the efficiency of different solvents for the extraction of lipids with the Soxhlet method and compare the lipid recovery productivities of Chlorella microalgae with thermal and physical pretreatments. The highest amount of lipids, 20.37% per dry sample, the microalga, the chlorella, the solvent mixture, the chloroform:methanol in a 1:2 ratio. The increase in the amount of lipids generated with the use of pretreatments no justifies its use for which it is recommended that no pretreatment be applied. The results allow to establish a baseline in the use of microalgae cultivable in the Ecuadorian mountain to obtain lipids for biofuels.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48256470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The state-of-the-art of computer libraries in the field of thermodynamic properties are based on the Helmholtz energy equation. Unfortunately, the use of high-level programming languages and its complex implementation often exceeds the memory limit of most microcontrollers. In this context, after examination of the behavior of five variants of the Peng-Robinson equation, a set of simple equations for the saturation properties of common refrigerants that exceeded the precision of the former ones were developed. The proposed correlations are directly programmable in C language, facilitating the implementation in microcontrollers. Several prototype equations were fitted to the thermodynamic data in the reference RefProp library for a few thermodynamics properties by means of a non-linear multiparametric least-squares fitting procedure. Finally, a discussion of the best function for each property, as well as the average and local coefficients and uncertainties have been reported for several common refrigerants.
{"title":"Aplicación de ecuaciones de estado cúbicas y desarrollo de correlaciones numéricas para el cálculo de propiedades termodinámicas en saturación de refrigerantes para su uso en microcontroladores","authors":"Javier García-del-Valle","doi":"10.18537/MSKN.09.02.09","DOIUrl":"https://doi.org/10.18537/MSKN.09.02.09","url":null,"abstract":"The state-of-the-art of computer libraries in the field of thermodynamic properties are based on the Helmholtz energy equation. Unfortunately, the use of high-level programming languages and its complex implementation often exceeds the memory limit of most microcontrollers. In this context, after examination of the behavior of five variants of the Peng-Robinson equation, a set of simple equations for the saturation properties of common refrigerants that exceeded the precision of the former ones were developed. The proposed correlations are directly programmable in C language, facilitating the implementation in microcontrollers. Several prototype equations were fitted to the thermodynamic data in the reference RefProp library for a few thermodynamics properties by means of a non-linear multiparametric least-squares fitting procedure. Finally, a discussion of the best function for each property, as well as the average and local coefficients and uncertainties have been reported for several common refrigerants.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42035287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Call Centers represent worldwide a consolidated industry and one of its activities is the management of collections. The present work proposes a predictive statistical model to increase the probability of phone contactability in the collection management through the best call schedule. This leads directly to consider more than two possibilities, that is, we are faced with a multicategorical response problem, so a multinomial model is specified. The cross-sectional data used in the empirical analysis comes from a large-scale collection company located in Ecuador. The individuals, object of this analysis, are borrowers who were in arrears in products of consumer credit and microcredit. The study includes the analysis of approximately 6000 individuals and the treatment of 139 explanatory variables collected between January and September 2016. The results suggest that historical contact information, day of the week, characteristics of debtors in arrears and propensity to pay (given by the ratio between arrears in short-term and in long-term) are determinants of an effective contact by phone.
{"title":"Optimización de contactos telefónicos efectivos en gestión de cobranzas mediante un modelo de mejor horario de llamada, usando regresión multinomial","authors":"Adriana Uquillas-Andrade, A. Carrera","doi":"10.18537/MSKN.09.01.09","DOIUrl":"https://doi.org/10.18537/MSKN.09.01.09","url":null,"abstract":"Call Centers represent worldwide a consolidated industry and one of its activities is the management of collections. The present work proposes a predictive statistical model to increase the probability of phone contactability in the collection management through the best call schedule. This leads directly to consider more than two possibilities, that is, we are faced with a multicategorical response problem, so a multinomial model is specified. The cross-sectional data used in the empirical analysis comes from a large-scale collection company located in Ecuador. The individuals, object of this analysis, are borrowers who were in arrears in products of consumer credit and microcredit. The study includes the analysis of approximately 6000 individuals and the treatment of 139 explanatory variables collected between January and September 2016. The results suggest that historical contact information, day of the week, characteristics of debtors in arrears and propensity to pay (given by the ratio between arrears in short-term and in long-term) are determinants of an effective contact by phone.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48568348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
espanolVarios autores consideran a la lectura como una actividad de suma importancia en la vida academica, profesional y personal de un ser humano. Leemos de todo, para nosotros mismos y para todos, sin embargo, los procesos perceptivos, la lateralizacion hemisferica, la vision y conciencia fonologica son factores intervinientes en la destreza de la lectura que pueden influir en la forma de adquisicion del aprendizaje de la misma. El objetivo principal de este estudio fue evaluar el efecto que produce el uso de las laminas de color Irlen® en la calidad del seguimiento ocular durante la lectura y la posible relacion con la lateralidad. Los participantes fueron cincuenta y tres (53) escolares de entre 6 y 7 anos, 32 con estres visual y 21 del grupo de referencia, a los cuales se les hizo examenes visuales estandarizados, pruebas de ceguera al color con el test Ishihara, la madurez neuropsicologica a traves del test CUMANES, sindrome Irlen o estres visual con EPLI1 y los movimientos oculares con la prueba K-D2. El analisis estadistico muestra que la lateralidad no esta relacionada con la capacidad lectora; existe mejorias significativas en el proceso perceptivo para la lectura con el uso del color; sin embargo, no se encontraron valores representativos para la comprension y numero de palabras por minuto. Hay diferencias significativas en la capacidad lectora entre ninos con Irlen y ninos sin Irlen, y se sugiere nuevos estudios que consideren habilidades atencionales, conciencia fonologica y memoria verbal en la lectura. EnglishSeveral authors consider reading an important activity in school, professional and personal life. Perceptual processes, hemispheric lateralization, vision and phonological awareness are factors that intervene in reading skills that can influence the way of learning. This study aimed to evaluate the effect of the use of Irlen color transparencies on the quality of ocular follow-up during reading and the possible relationship with laterality. Participants were fifty-three (53) children, 6 and 7 years old, respectively 32 children with Irlen Syndrome (IS) or visual stress and 21 children as the reference group. All children were subjected to a series of visual standard tests to assess color blindness (Ishihara test), neuropsychological maturity (CUMANES test), Irlen syndrome (IRPS test[1]) and rapid eye movement (K-D test[2]). Research results reveal that reading capacity is not related to laterality, the use of color significantly improves the perceptual process of reading, and differences in reading attainment is noteworthy between children with Irlen and children without Irlen syndrome. New studies are suggested to consider the effect of attentional abilities, phonological awareness and verbal memory in reading. [1] Irlen Reading Perceptual Scale test / Escala Perceptual de Lectura Irlen [2] King-Devick test / prueba King-Devick
{"title":"La relación del logro de la lectura con la lateralidad, el movimiento ocular sacádico y el color en los niños","authors":"René David Tacuri, Marcelo Bernal, R. Buñay","doi":"10.18537/MSKN.09.01.02","DOIUrl":"https://doi.org/10.18537/MSKN.09.01.02","url":null,"abstract":"espanolVarios autores consideran a la lectura como una actividad de suma importancia en la vida academica, profesional y personal de un ser humano. Leemos de todo, para nosotros mismos y para todos, sin embargo, los procesos perceptivos, la lateralizacion hemisferica, la vision y conciencia fonologica son factores intervinientes en la destreza de la lectura que pueden influir en la forma de adquisicion del aprendizaje de la misma. El objetivo principal de este estudio fue evaluar el efecto que produce el uso de las laminas de color Irlen® en la calidad del seguimiento ocular durante la lectura y la posible relacion con la lateralidad. Los participantes fueron cincuenta y tres (53) escolares de entre 6 y 7 anos, 32 con estres visual y 21 del grupo de referencia, a los cuales se les hizo examenes visuales estandarizados, pruebas de ceguera al color con el test Ishihara, la madurez neuropsicologica a traves del test CUMANES, sindrome Irlen o estres visual con EPLI1 y los movimientos oculares con la prueba K-D2. El analisis estadistico muestra que la lateralidad no esta relacionada con la capacidad lectora; existe mejorias significativas en el proceso perceptivo para la lectura con el uso del color; sin embargo, no se encontraron valores representativos para la comprension y numero de palabras por minuto. Hay diferencias significativas en la capacidad lectora entre ninos con Irlen y ninos sin Irlen, y se sugiere nuevos estudios que consideren habilidades atencionales, conciencia fonologica y memoria verbal en la lectura. EnglishSeveral authors consider reading an important activity in school, professional and personal life. Perceptual processes, hemispheric lateralization, vision and phonological awareness are factors that intervene in reading skills that can influence the way of learning. This study aimed to evaluate the effect of the use of Irlen color transparencies on the quality of ocular follow-up during reading and the possible relationship with laterality. Participants were fifty-three (53) children, 6 and 7 years old, respectively 32 children with Irlen Syndrome (IS) or visual stress and 21 children as the reference group. All children were subjected to a series of visual standard tests to assess color blindness (Ishihara test), neuropsychological maturity (CUMANES test), Irlen syndrome (IRPS test[1]) and rapid eye movement (K-D test[2]). Research results reveal that reading capacity is not related to laterality, the use of color significantly improves the perceptual process of reading, and differences in reading attainment is noteworthy between children with Irlen and children without Irlen syndrome. New studies are suggested to consider the effect of attentional abilities, phonological awareness and verbal memory in reading. [1] Irlen Reading Perceptual Scale test / Escala Perceptual de Lectura Irlen [2] King-Devick test / prueba King-Devick","PeriodicalId":33189,"journal":{"name":"Maskana","volume":"87 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41283778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
espanolEl uso indiscriminado de plaguicidas sinteticos en el control de plagas y enfermedades que afectan los cultivos, la salud humana, y el medio ambiente, han conducido a resistencia por parte de insectos y presencia de residuos toxicos en alimentos. Esto ha propiciado la necesidad de desarrollar enfoques alternativos para el control de especies plaga. El presente estudio investigo la actividad insecticida del aceite esencial de hojas de Lantana camara sobre el insecto Drosophila melanogaster. Se aislo aceite esencial de las hojas de L. camara utilizando el metodo de hidro-destilacion. El bioensayo se realizo por el metodo de la OMS para determinacion de actividad adulticida contra mosquitos y artropodos. Diferentes compuestos fueron identificados por analisis de cromatografia de gases-espectrometria de masas. El valor de CL50 del aceite fue 0.56 mg cm-2 mientras que el valor de CL95 fue 0.96 mg cm-2 sobre Drosophila melanogaster. El rendimiento de aceite esencial de hojas obtenido por hidro-destilacion fue 0.022% w/w. El analisis por cromatografia de gases - espectrometria de masas del aceite esencial mostro 66 picos, donde Germacren D (19.29%), B-Cariofileno (14.55%), α-Humuleno (9.51%), Biciclogermacren (8.94%), Germacren B (7.26%) y γ-Terpineno (5.62%) estuvieron presentes en mayores cantidades y contribuyeron con el 56.21% del total de los constituyentes. El aceite esencial de hojas de L. camara mostro actividad adulticida sobre la especie de mosca Drosophila melanogaster y podria ser utilizado para el desarrollo de insecticidas a base de aceite como complemento de insecticidas sinteticos para el control de moscas causantes de importantes perdidas economicas. EnglishThe indiscriminate use of synthetic pesticides in the control of pests and diseases affects crops, human health, and the environment, and lead to insect resistance and the presence of toxic residues in food. Previous generated the need to develop alternative approaches to pest species control. In the present study the insecticidal activity of the essential oil of leaves of Lantana camara on the insect model Drosophila melanogaster has been investigated. Essential oil was isolated from L. camara leaves using the hydro-distillation method. The Bioassay test was performed by the WHO method for the determination of adulticidal activity against mosquitoes and arthropods. Different compounds were identified by gas chromatography - mass spectrometry analysis. The LC50 value of the oil was 0.56 mg cm-2 whereas the value of the LC95 was 0.96 mg cm-2 on Drosophila melanogaster. The yield of leaf essential oil obtained by hydro-distillation was 0.022% w/w. Gas chromatography-mass spectrometry analysis of the essential oil showed 66 peaks, where Germacren D (19.29%), B-Caryophyllene (14.55%), α-Humulene (9.51%), Biciclogermacren (8.94%), Germacren B (7.26%) and γ-Terpinene (5.62%) were present in greater amounts and contributed 56.21% of the total constituents. The essential oil of L. cam
{"title":"Actividad adulticida y composición química del aceite esencial de hojas de Lantana camara sobre Drosophila melanogaster","authors":"A. Valdéz, E. Delgado, J. Ramirez","doi":"10.18537/MSKN.09.01.03","DOIUrl":"https://doi.org/10.18537/MSKN.09.01.03","url":null,"abstract":"espanolEl uso indiscriminado de plaguicidas sinteticos en el control de plagas y enfermedades que afectan los cultivos, la salud humana, y el medio ambiente, han conducido a resistencia por parte de insectos y presencia de residuos toxicos en alimentos. Esto ha propiciado la necesidad de desarrollar enfoques alternativos para el control de especies plaga. El presente estudio investigo la actividad insecticida del aceite esencial de hojas de Lantana camara sobre el insecto Drosophila melanogaster. Se aislo aceite esencial de las hojas de L. camara utilizando el metodo de hidro-destilacion. El bioensayo se realizo por el metodo de la OMS para determinacion de actividad adulticida contra mosquitos y artropodos. Diferentes compuestos fueron identificados por analisis de cromatografia de gases-espectrometria de masas. El valor de CL50 del aceite fue 0.56 mg cm-2 mientras que el valor de CL95 fue 0.96 mg cm-2 sobre Drosophila melanogaster. El rendimiento de aceite esencial de hojas obtenido por hidro-destilacion fue 0.022% w/w. El analisis por cromatografia de gases - espectrometria de masas del aceite esencial mostro 66 picos, donde Germacren D (19.29%), B-Cariofileno (14.55%), α-Humuleno (9.51%), Biciclogermacren (8.94%), Germacren B (7.26%) y γ-Terpineno (5.62%) estuvieron presentes en mayores cantidades y contribuyeron con el 56.21% del total de los constituyentes. El aceite esencial de hojas de L. camara mostro actividad adulticida sobre la especie de mosca Drosophila melanogaster y podria ser utilizado para el desarrollo de insecticidas a base de aceite como complemento de insecticidas sinteticos para el control de moscas causantes de importantes perdidas economicas. EnglishThe indiscriminate use of synthetic pesticides in the control of pests and diseases affects crops, human health, and the environment, and lead to insect resistance and the presence of toxic residues in food. Previous generated the need to develop alternative approaches to pest species control. In the present study the insecticidal activity of the essential oil of leaves of Lantana camara on the insect model Drosophila melanogaster has been investigated. Essential oil was isolated from L. camara leaves using the hydro-distillation method. The Bioassay test was performed by the WHO method for the determination of adulticidal activity against mosquitoes and arthropods. Different compounds were identified by gas chromatography - mass spectrometry analysis. The LC50 value of the oil was 0.56 mg cm-2 whereas the value of the LC95 was 0.96 mg cm-2 on Drosophila melanogaster. The yield of leaf essential oil obtained by hydro-distillation was 0.022% w/w. Gas chromatography-mass spectrometry analysis of the essential oil showed 66 peaks, where Germacren D (19.29%), B-Caryophyllene (14.55%), α-Humulene (9.51%), Biciclogermacren (8.94%), Germacren B (7.26%) and γ-Terpinene (5.62%) were present in greater amounts and contributed 56.21% of the total constituents. The essential oil of L. cam","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47508971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Mora, Verónica Pinos, Mohand Benachour, Carlos Magalhaes-Baltar
espanolEl plomo es un metal toxico y su remocion de los efluentes industriales es importante. Esta puede hacerse de varias formas, incluyendo la flotacion ionica por aire disuelto (FAS por sus siglas en ingles). Las ventajas de esta tecnica son multiples, entre ellas: su rapidez, eficiencia, bajo costo y poco espacio requerido. Las pruebas se realizaron con una solucion acuosa sintetica que simulaba el efluente de una empresa productora de baterias. Se utilizo como colector el xantato, muy usado en procesamiento de lodos minerales. Las variables estudiadas fueron el tamano de la cadena hidro carbonica del xantato, la concentracion de xantato, pH, el tiempo de contacto xantato-plomo y la concentracion de espumante. La determinacion del contenido de plomo residual fue obtenida usando la tecnica de espectrofotometria de absorcion atomica. El metodo propuesto demostro que la flotacion por aire disuelto es eficiente para la remocion del ion plomo, pudiendose aplicar no solo en la separacion de lodos minerales, como se ha estado usando hasta ahora, sino tambien en tecnicas de remocion de metales de efluentes. A partir de una solucion con 20 mg L-1 de Pb fue posible una reduccion del contenido en 0.65 mg L-1, es decir, se produjo una remocion del 96.8% de la concentracion inicial. EnglishLead is a toxic metal and its removal from industrial effluents is important. This can be done in several ways including ion dissolved air flotation (DAF). The advantages of the latter are multiple, among them speed, efficiency, low cost and space requirement. Tests were carried out with an aqueous synthetic wastewater of lead nitrate simulating the effluent of a producer of batteries. Xanthate was used as collector, a widely applied approach in ore processing. The variables studied were the size of the hydrocarbon chain of xanthate, xanthate concentration, pH, contact time, and foaming concentration. Quantification of residual lead was obtained by atomic adsorption. The proposed method revealed that dissolved air flotation is an efficient technique for the removal of lead ions, like the technique at the present is successful used in ore separation. It was observed that the pH and the amount of foaming did not have an effect. However, a solution of 20 mg L-1 of Pb could be reduced to 0.65 mg L-1, corresponding to a removal of 96.8% of the initial concentration. Keywords: Lead removal, ion flotation, dissolved air flotation, DAF, flotation, xanthate, wastewater treatment.
{"title":"Remoción de plomo de un efluente sintético vía flotación iónica utilizando xantato","authors":"E. Mora, Verónica Pinos, Mohand Benachour, Carlos Magalhaes-Baltar","doi":"10.18537/MSKN.09.01.04","DOIUrl":"https://doi.org/10.18537/MSKN.09.01.04","url":null,"abstract":"espanolEl plomo es un metal toxico y su remocion de los efluentes industriales es importante. Esta puede hacerse de varias formas, incluyendo la flotacion ionica por aire disuelto (FAS por sus siglas en ingles). Las ventajas de esta tecnica son multiples, entre ellas: su rapidez, eficiencia, bajo costo y poco espacio requerido. Las pruebas se realizaron con una solucion acuosa sintetica que simulaba el efluente de una empresa productora de baterias. Se utilizo como colector el xantato, muy usado en procesamiento de lodos minerales. Las variables estudiadas fueron el tamano de la cadena hidro carbonica del xantato, la concentracion de xantato, pH, el tiempo de contacto xantato-plomo y la concentracion de espumante. La determinacion del contenido de plomo residual fue obtenida usando la tecnica de espectrofotometria de absorcion atomica. El metodo propuesto demostro que la flotacion por aire disuelto es eficiente para la remocion del ion plomo, pudiendose aplicar no solo en la separacion de lodos minerales, como se ha estado usando hasta ahora, sino tambien en tecnicas de remocion de metales de efluentes. A partir de una solucion con 20 mg L-1 de Pb fue posible una reduccion del contenido en 0.65 mg L-1, es decir, se produjo una remocion del 96.8% de la concentracion inicial. EnglishLead is a toxic metal and its removal from industrial effluents is important. This can be done in several ways including ion dissolved air flotation (DAF). The advantages of the latter are multiple, among them speed, efficiency, low cost and space requirement. Tests were carried out with an aqueous synthetic wastewater of lead nitrate simulating the effluent of a producer of batteries. Xanthate was used as collector, a widely applied approach in ore processing. The variables studied were the size of the hydrocarbon chain of xanthate, xanthate concentration, pH, contact time, and foaming concentration. Quantification of residual lead was obtained by atomic adsorption. The proposed method revealed that dissolved air flotation is an efficient technique for the removal of lead ions, like the technique at the present is successful used in ore separation. It was observed that the pH and the amount of foaming did not have an effect. However, a solution of 20 mg L-1 of Pb could be reduced to 0.65 mg L-1, corresponding to a removal of 96.8% of the initial concentration. Keywords: Lead removal, ion flotation, dissolved air flotation, DAF, flotation, xanthate, wastewater treatment.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45355586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Los cambios relacionados con la edad en los valores hematologicos se producen en casi todas las especies de mamiferos, y los estudios publicados que incluyen mediciones repetidas de los parametros hematologicos en terneras durante los primeros meses de vida son limitados. El objetivo de la presente investigacion fue determinar los valores hematologicos con mediciones secuenciales, desde el nacimiento hasta los 6 meses de edad, en terneras de la raza Holstein frisian mestizas, en la granja de Nero ubicada a 3,000 msnm. Se tomaron muestras de sangre a 36 terneras clinicamente sanas, las pruebas hematologicas se realizaron en contadores celulares automaticos de uso veterinario y calibrado para la especie bovina. Los resultados fueron procesados mediante el software SPSS version 22, en el se calcularon los valores descriptivos minimos, maximos, el promedio y la desviacion estandar para la edad en dias y los valores hematologicos. Ademas de los estadisticos descriptivos, se aplico la prueba de Correlacion de Pearson para establecer si existe correlacion entre los valores evaluados con respecto a la edad. Los niveles de significancia se establecieron a dos colas tanto para p≤0.01(**) como para p≤0.05(*). Como conclusion se puede manifestar que la mayoria de las correlaciones evidenciadas presenta una asociacion baja con la edad, sin embargo, el VCM1 tiene una asociacion media (Correlacion de Pearson -0.531**, R2 = 0.28), misma que disminuye a medida que aumenta la edad de las terneras.
{"title":"Estudio exploratorio de valores hematológicos en terneras Holstein Frisian mestizas, durante los primeros seis meses de vida","authors":"E. Palacios, Jhonny Narváez","doi":"10.18537/MSKN.09.01.06","DOIUrl":"https://doi.org/10.18537/MSKN.09.01.06","url":null,"abstract":"Los cambios relacionados con la edad en los valores hematologicos se producen en casi todas las\u0000especies de mamiferos, y los estudios publicados que incluyen mediciones repetidas de los parametros\u0000hematologicos en terneras durante los primeros meses de vida son limitados. El objetivo de la presente\u0000investigacion fue determinar los valores hematologicos con mediciones secuenciales, desde el\u0000nacimiento hasta los 6 meses de edad, en terneras de la raza Holstein frisian mestizas, en la granja de\u0000Nero ubicada a 3,000 msnm. Se tomaron muestras de sangre a 36 terneras clinicamente sanas, las\u0000pruebas hematologicas se realizaron en contadores celulares automaticos de uso veterinario y calibrado\u0000para la especie bovina. Los resultados fueron procesados mediante el software SPSS version 22, en el\u0000se calcularon los valores descriptivos minimos, maximos, el promedio y la desviacion estandar para la\u0000edad en dias y los valores hematologicos. Ademas de los estadisticos descriptivos, se aplico la prueba\u0000de Correlacion de Pearson para establecer si existe correlacion entre los valores evaluados con respecto\u0000a la edad. Los niveles de significancia se establecieron a dos colas tanto para p≤0.01(**) como para\u0000p≤0.05(*). Como conclusion se puede manifestar que la mayoria de las correlaciones evidenciadas\u0000presenta una asociacion baja con la edad, sin embargo, el VCM1\u0000tiene una asociacion media (Correlacion\u0000de Pearson -0.531**, R2 = 0.28), misma que disminuye a medida que aumenta la edad de las terneras.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47490519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Romo, A. Orellana, Lourdes Huiracocha, Victoria Abril-Ulloa
Ecuador is a country in nutritional transition. National data show that the prevalence of overweight and obesity more than triples from the preschool to school-aged years, while stunting remains prevalent. A cross-sectional study in the municipal preschools in Cuenca was conducted to better understand the contributing factors to this nutritional transition. Of the 97 children in the sample population, 5.3% were overweight or obese and 8.5% were stunted. Despite no underweight children, 19.0% of the parents or caregivers considered their child to be underweight. Most households had some degree of food insecurity (71.4%). Parents reported that most children drank water daily at home (70.5%), but according to the teachers, less than half drank water at school daily (41.5%). Parents and teachers, respectively, reported that 89.5% and 34.7% of the children consumed vegetables daily and 70.5% and 57.9% consumed fruit daily at home or school. About three-quarters of the parents and teachers reported that children dedicated ≥1 hour daily to physical activity, at home and school. Half of the parents reported that their child spent at least 2 hours per day watching the television, using an electronic tablet or computer. Stool examination showed that 26.1% of children were positive for Helicobacter pylori antigen and 19.3% for intestinal parasites. This study provided insight into potential areas to focus health education and promotion among this population, for example, in diet and physical activity habits. However, other important factors including poverty related risk factors, such as household food insecurity, and high prevalence of Helicobacter pylori infection and intestinal parasitosis, should be considered simultaneously in such efforts.
{"title":"Demographic characteristics, nutritional status, dietary and physical activity habits, Helicobacter pylori infection, and intestinal parasitosis among children at municipal preschools in Cuenca, Ecuador","authors":"M. Romo, A. Orellana, Lourdes Huiracocha, Victoria Abril-Ulloa","doi":"10.18537/MSKN.09.01.05","DOIUrl":"https://doi.org/10.18537/MSKN.09.01.05","url":null,"abstract":"Ecuador is a country in nutritional transition. National data show that the prevalence of overweight and obesity more than triples from the preschool to school-aged years, while stunting remains prevalent. A cross-sectional study in the municipal preschools in Cuenca was conducted to better understand the contributing factors to this nutritional transition. Of the 97 children in the sample population, 5.3% were overweight or obese and 8.5% were stunted. Despite no underweight children, 19.0% of the parents or caregivers considered their child to be underweight. Most households had some degree of food insecurity (71.4%). Parents reported that most children drank water daily at home (70.5%), but according to the teachers, less than half drank water at school daily (41.5%). Parents and teachers, respectively, reported that 89.5% and 34.7% of the children consumed vegetables daily and 70.5% and 57.9% consumed fruit daily at home or school. About three-quarters of the parents and teachers reported that children dedicated ≥1 hour daily to physical activity, at home and school. Half of the parents reported that their child spent at least 2 hours per day watching the television, using an electronic tablet or computer. Stool examination showed that 26.1% of children were positive for Helicobacter pylori antigen and 19.3% for intestinal parasites. This study provided insight into potential areas to focus health education and promotion among this population, for example, in diet and physical activity habits. However, other important factors including poverty related risk factors, such as household food insecurity, and high prevalence of Helicobacter pylori infection and intestinal parasitosis, should be considered simultaneously in such efforts.","PeriodicalId":33189,"journal":{"name":"Maskana","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49334760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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