A. J. Sandoval, J. A. Barreiro, A. D. Sousa, D. Blanco, C. Giménez
Water sorption data of the peeled bean and shell of Trinitario fermented and dry cocoa beans were determined at 25 °C and adjusted to the isotherm models of Brunauer-Emmet-Teller-(BET) and Guggenheim-Anderson-de Boer-(GAB). The difference in the moisture sorption capacity of the shell and peeled beans was clearly established. The monolayer water contents estimated using the BET and GAB models for the peeled bean was 3.53 and 3.60 g water/100 g dry solids, respectively; while for the shell were 8.42 and 8.50 g water/100 g dry solids. The energy constants (C) obtained applying the BET model for the peeled bean and shell were 154.3 and 163.2, respectively. Those estimated from the GAB model (C ́) were 21.63 and 83.56, respectively. A larger C ́ value for the shell indicates stronger water binding to the active sites in the monolayer as compared with the peeled beans that could indicate the presence of more active polar sites in the former. The value of the K constant in the GAB model was 0.871 and 0.942 for the peeled bean and shell respectively that could suggest a larger water adsorption by proteinaceous material in the peeled bean.
{"title":"Sorption characteristics of peeled beans and shells of fermented and dry Trinitario cocoa beans (Theobroma cacao L.)","authors":"A. J. Sandoval, J. A. Barreiro, A. D. Sousa, D. Blanco, C. Giménez","doi":"10.22209/rt.v43n1a07","DOIUrl":"https://doi.org/10.22209/rt.v43n1a07","url":null,"abstract":"Water sorption data of the peeled bean and shell of Trinitario fermented and dry cocoa beans were determined at 25 °C and adjusted to the isotherm models of Brunauer-Emmet-Teller-(BET) and Guggenheim-Anderson-de Boer-(GAB). The difference in the moisture sorption capacity of the shell and peeled beans was clearly established. The monolayer water contents estimated using the BET and GAB models for the peeled bean was 3.53 and 3.60 g water/100 g dry solids, respectively; while for the shell were 8.42 and 8.50 g water/100 g dry solids. The energy constants (C) obtained applying the BET model for the peeled bean and shell were 154.3 and 163.2, respectively. Those estimated from the GAB model (C ́) were 21.63 and 83.56, respectively. A larger C ́ value for the shell indicates stronger water binding to the active sites in the monolayer as compared with the peeled beans that could indicate the presence of more active polar sites in the former. The value of the K constant in the GAB model was 0.871 and 0.942 for the peeled bean and shell respectively that could suggest a larger water adsorption by proteinaceous material in the peeled bean.","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"50 1","pages":"49-55"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84311890","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}
{"title":"Modelo CFD para caracterizar el transporte del retardante de llama BDE 99 en una laguna facultativa usada para el tratamiento de aguas residuales municipales","authors":"Andrés Mauricio Zapata Rivera, M. P. Varón","doi":"10.22209/rt.v43n1a06","DOIUrl":"https://doi.org/10.22209/rt.v43n1a06","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"22 1","pages":"41-48"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81204978","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}
Charity Elizabeth Andrade Ruiz, A. Cáceres, Alexandra Lisbet Vera Bonilla, G. Araujo, E. M. Avendaño
Plants can remove metals from aqueous systems, based on strategies such as metal exclusion; or by its accumulation in leaves and pseudostem in non-toxic form. The capacity of phytosorption and translocation of Pistia stratiotes and Eichhornia crassipes was evaluated, exposing them to Cr(VI): 5, 10, 25 and 50 mgL -1 . The experimental units consisted of glass bottles containing 0.5L of synthetic effluent, fertilizer and one plant per container. These were maintained with luminous intensity 106±23 μmol quanta m s -1 , light: darkness periods: 12:12h, and 28±2ºC. The determination of Cr(VI) was carried out in the medium, at the beginning and every 24h, for 10 days. The Cr(total) in plant was determined at the end of the treatment. The biggest removal was obtained using Eichhornia with 98.0 and 97.1% in the treatments at 5 and 10 mgCr (VI) L -1 , respectively. While for the same, Pistia removed 80.2 and 74.0%. The highest bioaccumulation was observed at the root level, with a bioaccumulation factor (FB) between 360-370 for Pistia and 490-708 for Eichhornia . Both plants achieved low values for translocation factor (FT<0.1). The plants showed an efficient bioaccumulation of the metal, following an exclusion mechanism that allows their photosynthetic apparatus not to be affected during the treatment.
植物可以通过诸如金属排斥等策略从水系统中去除金属;或在叶片和假茎中以无毒形式积累。在Cr(VI): 5、10、25和50 mg / l -1的条件下，对层状Pistia stratiotes和Eichhornia crassipes的植物吸收和转运能力进行了评价。实验装置由装有0.5L合成废水和肥料的玻璃瓶和每个容器一株植物组成。发光强度为106±23 μmol量子m s -1，明暗时间为12:12h，温度为28±2ºC。在培养液中测定Cr(VI)，每24h测定一次，连续测定10天。处理结束时测定植株总铬含量。在5 mgCr (VI) L -1和10 mgCr (VI) L -1处理下，Eichhornia的去除率分别为98.0%和97.1%。而在相同的情况下，Pistia分别去除了80.2%和74.0%。根水平的生物积累量最高，雌豆属植物的生物积累因子(FB)在360 ~ 370之间，青花属植物的FB在490 ~ 708之间。两种植物的转运因子均较低(FT<0.1)。植物表现出高效的金属生物积累，遵循一种排除机制，使它们的光合器官在处理期间不受影响。
{"title":"Fitoacumulación y translocación de cromo en Eichhornia crassipes y Pistia stratiotes durante el tratamiento de efluentes contaminados","authors":"Charity Elizabeth Andrade Ruiz, A. Cáceres, Alexandra Lisbet Vera Bonilla, G. Araujo, E. M. Avendaño","doi":"10.22209/rt.v43n1a04","DOIUrl":"https://doi.org/10.22209/rt.v43n1a04","url":null,"abstract":"Plants can remove metals from aqueous systems, based on strategies such as metal exclusion; or by its accumulation in leaves and pseudostem in non-toxic form. The capacity of phytosorption and translocation of Pistia stratiotes and Eichhornia crassipes was evaluated, exposing them to Cr(VI): 5, 10, 25 and 50 mgL -1 . The experimental units consisted of glass bottles containing 0.5L of synthetic effluent, fertilizer and one plant per container. These were maintained with luminous intensity 106±23 μmol quanta m s -1 , light: darkness periods: 12:12h, and 28±2ºC. The determination of Cr(VI) was carried out in the medium, at the beginning and every 24h, for 10 days. The Cr(total) in plant was determined at the end of the treatment. The biggest removal was obtained using Eichhornia with 98.0 and 97.1% in the treatments at 5 and 10 mgCr (VI) L -1 , respectively. While for the same, Pistia removed 80.2 and 74.0%. The highest bioaccumulation was observed at the root level, with a bioaccumulation factor (FB) between 360-370 for Pistia and 490-708 for Eichhornia . Both plants achieved low values for translocation factor (FT<0.1). The plants showed an efficient bioaccumulation of the metal, following an exclusion mechanism that allows their photosynthetic apparatus not to be affected during the treatment.","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77552861","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}
W. Cando, Lenys Fernández, Patricio Bonilla, Gustavo Yánez, J. Bucheli, A. Muñoz, María Fernanda Orquera, Patricio Espinoza-Montero
{"title":"Efecto de la incorporación por vía seca de residuos de caucho obtenido tras su remoción de una pista de aterrizaje de aeropuerto en un asfalto AC-20","authors":"W. Cando, Lenys Fernández, Patricio Bonilla, Gustavo Yánez, J. Bucheli, A. Muñoz, María Fernanda Orquera, Patricio Espinoza-Montero","doi":"10.22209/rt.v43n1a01","DOIUrl":"https://doi.org/10.22209/rt.v43n1a01","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"63 1","pages":"3-11"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73075838","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}
P. M. Ferres, Antonio Medina Rivilla, Nathaly Vera-Gajardo
{"title":"Estadística aplicada: Validación de la escala de Fischer, King y Tague en estudiantes de ingeniería","authors":"P. M. Ferres, Antonio Medina Rivilla, Nathaly Vera-Gajardo","doi":"10.22209/rt.ve2019a02","DOIUrl":"https://doi.org/10.22209/rt.ve2019a02","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"21 1","pages":"160-167"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74162937","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}
Roberto Torres Hoyer, Jesús Torres Hoyer, F. Bongiorno, J. Peña, Oswaldo Peña, L. González, R. Picón, Wilmer Barreto
{"title":"Evaluación del riesgo vehicular por desprendimientos de rocas en taludes, Carretera Rafael Caldera, Mérida, Venezuela","authors":"Roberto Torres Hoyer, Jesús Torres Hoyer, F. Bongiorno, J. Peña, Oswaldo Peña, L. González, R. Picón, Wilmer Barreto","doi":"10.22209/rt.ve2019a08","DOIUrl":"https://doi.org/10.22209/rt.ve2019a08","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"360 1","pages":"203-208"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76421538","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}
Systems that involve waiting before attention are framed within the Theory of queues. This work seeks to compare performance measures in non-Markovian queues. For this, single-tail systems were simulated, which were formed from the combinations of time distributions between arrivals (normal, lognormal, Weibull or triangular), their parameters (Test 1, Test 2 or Test 3), and the distributions of service times (constant or triangular). Some results show that when comparing each performance measure individually, for systems that maintain constant arrival parameters, service distributions, and vary the distribution of time between arrival, their joint behavior is statistically different. On the other hand, the systems that included normal or uniform input distributions, setting the distribution parameters with one or two standard deviations (1σ; 2 σ), and the service distribution, showed that in the evaluation of each measure of particular performance, had statistically equal values. In the case of the systems that included the parameters with the highest standard deviation and the lognormal and Weibull, or lognormal and uniform distributions, they presented statistically similar behavior in three of four performance measures.
{"title":"Comparison of performance measures in non-Markovian queues","authors":"D. Lagos, R. Mancilla, P. Leal","doi":"10.22209/rt.ve2019a16","DOIUrl":"https://doi.org/10.22209/rt.ve2019a16","url":null,"abstract":"Systems that involve waiting before attention are framed within the Theory of queues. This work seeks to compare performance measures in non-Markovian queues. For this, single-tail systems were simulated, which were formed from the combinations of time distributions between arrivals (normal, lognormal, Weibull or triangular), their parameters (Test 1, Test 2 or Test 3), and the distributions of service times (constant or triangular). Some results show that when comparing each performance measure individually, for systems that maintain constant arrival parameters, service distributions, and vary the distribution of time between arrival, their joint behavior is statistically different. On the other hand, the systems that included normal or uniform input distributions, setting the distribution parameters with one or two standard deviations (1σ; 2 σ), and the service distribution, showed that in the evaluation of each measure of particular performance, had statistically equal values. In the case of the systems that included the parameters with the highest standard deviation and the lognormal and Weibull, or lognormal and uniform distributions, they presented statistically similar behavior in three of four performance measures.","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88820876","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}
L. González, W. Peñaloza, M. E. Perdomo, F. Bongiorno, Roberto Torres
{"title":"Evidencias Tectono-Estructurales y Morfológicas del Corrimiento de Mesa Bolívar en la Zona de Chiguará del Estado Mérida","authors":"L. González, W. Peñaloza, M. E. Perdomo, F. Bongiorno, Roberto Torres","doi":"10.22209/rt.ve2019a10","DOIUrl":"https://doi.org/10.22209/rt.ve2019a10","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"16 1","pages":"213-219"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81643715","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}
Armando E. González, M. Placencia, N. Arancibia-Miranda, Cedenna Santiago Chile. Nanotechnology
{"title":"Catalizadores bifuncionales a base de imogolita, Ni y Mo para el mejoramiento de las propiedades fisicoquímicas del bio-aceite proveniente de cáscara de avena","authors":"Armando E. González, M. Placencia, N. Arancibia-Miranda, Cedenna Santiago Chile. Nanotechnology","doi":"10.22209/rt.ve2019a04","DOIUrl":"https://doi.org/10.22209/rt.ve2019a04","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"75 1","pages":"175-180"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88518106","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. Echeverria, L. Romero, P. Hidalgo, A. Sánchez, R. Hunter
{"title":"Síntesis asistida por microondas de epoxidados obtenidos a partir de lípidos de lodos de aguas residuales domiciliarias para el desarrollo de resinas epóxicas","authors":"A. Echeverria, L. Romero, P. Hidalgo, A. Sánchez, R. Hunter","doi":"10.22209/rt.ve2019a11","DOIUrl":"https://doi.org/10.22209/rt.ve2019a11","url":null,"abstract":"","PeriodicalId":21456,"journal":{"name":"Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia","volume":"72 1","pages":"220-224"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81667440","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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