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Search Results: 1 - 10 of 15428 matches for " Yordanka Reyes Cruz "
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Biodiesel Production Based in Microalgae: A Biorefinery Approach  [PDF]
Lauren Espinosa González, Gisel Chenard Díaz, Donato Alexandre Gomes Aranda, Yordanka Reyes Cruz, Mariana Monteiro Fortes
Natural Science (NS) , 2015, DOI: 10.4236/ns.2015.77039
Abstract: It is of great knowledge nowadays that the use of fossil fuels is responsible for the emission of gases that intensify the greenhouse effect, which threatens the survival of the humankind. The gravity of this fact could be mitigated through the indirect use of solar energy for fuels derived from vegetable that can be planted and cultivated by the world of renewable and non-polisher. Microalgae play an important role in this regard, as they have promising characteristics as potential raw material for the production of biofuels, able to absorb large amounts of CO2. Chlorophyll organisms convert these simple substances in the atmosphere, absorbing sunlight into chemical energy stored, that is, compounds with high energy, biomass can also be used to obtain biocompounds human nutritional supplement and food animal, however, have been found an important number of difficulties to economically viable production like high cost of production of dry biomass and oil extraction. Here, we review the main approaches of biorefinery concept appearing as an alternative to achieve economic viability of the production of bio-diesel based on microalgae. The major points are the following: 1) use of re-residual water, 2) marketing of Carbon Credits, and 3) development of co-products resulting from high value added.
Primary Separation of Antioxidants (Unsaponifiables) the Wet Biomass Microalgae Chlamydomonas sp. and Production of the Biodiesel  [PDF]
Gisel Chenard Díaz, Yordanka Reyes Cruz, Mariana Monteiro Fortes, Carolina Vieira Viegas, René González Carliz, Nelson C. Furtado, Donato A. Gomes Aranda
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.615108
Abstract: This work studies the saponification which directs the wet biomass of algae Chlamydomonas sp. like a previous stage to production of biodiesel. This stage allows the obtainment of fatty acids to produce biodiesel, instead of the gross lipid fraction. In addition of the fatty acids, utilizing the same process one can also obtain the fraction unsaponifiable, these are soluble in apolar solvents and contain mainly carotenoids that can take action as antioxidants and photoprotectors, as they reduce the oxidation of unsaturated fatty acids. The saponification direct and extraction of fatty acids from biomass is faster and reduces the time and cost of operation. The separation of unsaponifiable matter from the biomass humid of microalgae Chlamydomonas sp., was held according to the method AOCS (Ca 6a-40), using extraction Liquid-liquid with hexane as solvent. Subsequently, phase hydroalcoholic or from soap, containing fatty acids, was acidified by addition of H2SO4 and the fatty acids were recovered by the addition of hexane. After acidulation of the soap, necessary for obtaining of the fatty acids was performed the stage of esterification for obtaining of biodiesel. The operating conditions were: molar ratio fatty acid:methanol (1:10), as catalyst 8% H2SO4 calculated in relation to the mass of fatty acid, 200 and reaction time of 90 minutes. The content of methyl esters was 96.8% determined by gas chromatography according to standard EN14103. The quality of biodiesel produced from wet biomass of Chlamydomonas sp. is according to the specification established by standard EN 14214 and RANP No. 14. For the identification of the composition the unsaponifiable fraction was used the method of High Performance Liquid Chromatography (HPLC). The composition of the material unsaponifiable found was of: Carotenoids total (0.76%); Lutein (0.45%); Zeaxanthin (0.07%); α-carotene (0.05%); β-carotene (0.11%); 13 cisβ-carotene (0.05%) and 9-cisβ-carotene (0.03%).
Neyda de la Caridad Om Tapanes,Donato Alexandre Gomes Aranda,Rodolfo Salazar Perez,Yordanka Reyes Cruz
Acta Scientiae et Technicae , 2013,
Abstract: Since the birth of the environmentalist movement, and, specially after the oil crisis in the 70s, alternative forms of energy have been discussed in order to substitute fossil fuels. One of these alternative fuels, Biodiesel, had its production and consume determined in the form of the law 11.097/05. In this paper, we discuss the current state of the art of Biodiesel in Brazil.
Cultivation of Microalgae Monoraphidium sp., in the Plant Pilot the Grand Valle Bio Energy, for Biodiesel Production  [PDF]
Gisel Chenard Díaz, Yordanka Reyes Cruz, René González Carliz, Rosa C. Vitorino de Paula, Donato A. Gomes Aranda, Marcellus A. G. Dario, Gustavo Saraiva Marass, Nelson C. Furtado
Natural Science (NS) , 2015, DOI: 10.4236/ns.2015.77040
Abstract: At present, Brazil imports approximately 11 billion liters/year of diesel. With the interruption of the works in the new Petrobras refineries, the projection is that by 2025 this volume will increase to 24.2 billion liters of diesel/year. In this sense, the biodiesel factory Grand Valle Bio Energy Ltda., located in the state of Rio de Janeiro, in conjunction with the FAPERJ makes some investments in technology development for the cultivation and use of microalgae as an alternative raw material in the production of biodiesel. Based on arguments previously said, this work presents the results of the microalgae cultivation Monoraphidium sp. in photobioreactors the pilot plant of the company. The installation with an area of 120 m2 is included with 2 open photobioreactors of type falling film (20 m × 1 m), with a cascade of 18mm and capacity of 4000 L. The lineage cultivated is selected from previous ecophysiological studies that are identified as promising for biodiesel production by having a high potential for the production of lipids. This lineage is maintained at collection of the stock of cultures Laboratory of Green Technologies of the School of Chemistry/ UFRJ. The cultivation was performed in means ASM-1 (Gorham et al., 1964), initial pH 8.0, with aeration and circulation average of 8 hours a day during 19 days. The culture was started with an inoculum of 1 × 107 cel/ml. The lipid production was determined in two phases of growth: on day 4 (exponential phase) and 15 day (stationary phase). For the determination and quantification of lipid content, two different methods were assessed for a sample of biomass, submitted to the same processes the separation and drying. The results showed the methodology of Bligh & Dyer with modifications as the most efficient in extracting lipids. The total lipid content of the biomass Monoraphidium sp. was 30.58%. The growth rate varied between 0.74 ± 0.01 and 0.68 ± 0.02.
Photobioreactor of Microalgas for CO2 Biofixation  [PDF]
Yordanka Reyes Cruz, Gisel Chenard Díaz, Andreina Z. Figuera Leonett, René Gonzalez Carliz, Vinicius Rossa, Luciano Basto Oliveira, Maurílio Novais da Paix?o, Donato Alexandre Gomes Aranda
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.71006
Abstract: Microalgae are unicellular organisms capable of photosynthesis, turning sunlight and carbon dioxide (CO2) into rich biomass. Precisely because of this definition, in recent years various sectors have been targeting their ability to reduce CO2 emissions and the capacity of simultaneously synthesize biomass which can be later used to produce bio-fuels. Besides being considered fast-growth microorganisms, microalgae have a diverse biochemical composition with similar characteristics to traditional biomass. In this context, the present work aimed to evaluate the biofixation of CO2 by the microalgae Monoraphidium sp., cultivated in a closed-window type photobioreactor, as well as characterization of microalgal biomass produced in relation to the total lipid content (TL), lipids converted into biodiesel (LCB), carbohydrates and proteins. The results achieved showed that the best result was obtained after 24 h of cultivation, where for each gram of biomass produced approximately 1.2 g of CO2 were consumed. In the growth phase the average biomass productivity in the Janela photobioreactor was 58 mg·L-1·day-1 concluding that microalgae culture systems could be coupled to the chimneys of large industries emitters CO2 using this gas, resulting from combustion processes, in the process of photosynthesis. The biomass Monoraphidium sp. produced had a content of lipids converted into biodiesel of approximately 8.36% ± 2.69%, carbohydrates 32% ± 3.37% and proteins 34.26% ± 0.41%.
Hydroesterification of Nannochloropsis oculata microalga’s biomass to biodiesel on Al2O3 supported Nb2O5 catalyst  [PDF]
Angel Almarales, Gisel Chenard, Roberto Abdala, Donato A. Gomes, Yordanka Reyes, Neyda Om Tapanes
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.44031
Abstract: Hydroesterification process has been presented biodiesel production from oil the green microalga Nannochloropsis oculata raw materials. Biodiesel studied in this work is the main product got from the hydroesterification of biomass the Nannochloropsis oculata and was obtained from esterification of fatty acid (product of a hydrolysis reaction) with methanol. It was used as catalyst the niobic acid pure and supported on δ-aluminum. The product was evaluated by gas chromatography and other analyses. The optimum conditions found in the conversion (%) for the hydrolysis reactions of the biomass (92.3%). Better results were observed in the algae concentration 20%, lead at 300?C with 20% of catalyst. For esterification of fatty acids of Nannochloropsis oculata (92.24%), were observed the molar ratio methanol: fat acid 3, lead at 200°C with 20% of catalyst supported.
Ventral Tegmental Area Neuronal Activity Correlates to Animals’ Behavioral Response to Chronic Methylphenidate Recorded from Adolescent SD Male Rats  [PDF]
Zachary Jones, Cruz Reyes Vazquez, Nachum Dafny
Journal of Behavioral and Brain Science (JBBS) , 2014, DOI: 10.4236/jbbs.2014.44020
Abstract: Methylphenidate (MPD) is considered as the first-line pharmacotherapy to treat ADHD. More recently, MPD has also been used as a cognitive enhancement recreationally. Its therapeutic effects are not fully understood, nor are the long term effects of the drug on brain development. The ventral tegmental area (VTA) neuronal activity was recorded from freely behaving adolescent rats using a wireless recording system. Five groups were used: saline, 0.6, 2.5, 5.0 and 10.0 mg/kg MPD. The experiment lasted for 10 days. This study demonstrated that VTA neurons respond to MPD in a dose response characteristic and the same dose of MPD can cause both behavioral sensitization and behavioral tolerance. The neuronal unit activity was evaluated based on the animals’ behavioral activity following chronic MPD administration. The study showed that the animals’ behavioral response to different acute MPD of 0.6, 2.5 and 10.0 mg/kg doses responded in a dose response characteristics. Moreover, the same chronic dose of 0.6, 2.5, and 10.0 mg/kg MPD elicits in some animals’ behavioral sensitization and in some others behavioral tolerance. Therefore, the neuronal activity recorded from animals expressing behavioral sensitization was analyzed separately from the neuronal activity recorded from of behaviorally tolerant animals and it was found that the VTA units of the behaviorally sensitization animals responded significantly different to the drug than those VTA units recorded from animals expressing behavioral tolerance.
Greis Julieth Cruz Reyes
Gondola : Ense?anza y Aprendizaje de las Ciencias , 2010,
Abstract: Describes the construction of an air cushion table with a working guide that encourages the development of certain thinking skills which allow greater depth in the concepts through which mental models are descriptions own simulations based on different physical phenomena , this assembly creates a cushion of air that results in movement without friction, magnets on the surface chips off the table. The work guides give the guidelines leading to analyze simulations of physical phenomena where the dissipative factors can be considered approximately zero. The present article describes the construction of the air cushion and some applications to the introduction of concepts such as, gas pressure, relationship pressure volume and random motion of particles.
De la Brigada Médica Cubana Parirenyatwa Group Hospital en Zimbabwe. 2012. X Jornada Científica en Zimbabwe/Harare From “Parirenyatwa Group Hospital” Cuban Medical Brigade in Zimbabwe 2012. 10th Scientific Event in Zimbabwe/Harare
Marcelina Cruz Reyes
Revista de Ciencias M??dicas de Pinar del R?-o , 2012,
Ni con dios ni con el diablo : Tales of survival, resistance, and rebellion from a reluctant academic
Mariolga Reyes Cruz
Decolonization : Indigeneity, Education & Society , 2012,
Abstract: Contemporary social movements challenge dominant ideas about democracy, freedom, independence, and autonomy as the daily experiences of the marginalized show these ideas have not lead to decolonization. When one examines academic knowledge production and academic institutions, common assumptions about “autonomy” and “freedom” clash with the expectation to submit to institutionalized cannons. At issue here are the ways in which the academic establishment reproduces the coloniality of power. For radical sociologist Aníbal Quijano, coloniality of power is a pattern of domination that articulates the multiple forms of exploitation that took hold at a global scale with the conquest of Abia Yala (The Americas). As Lao-Montes (2010) explains, the exploitation of work by capital, as a pattern of coloniality, is expressed in all forms of labor organization that are subordinated to the process of accumulation of global capital. For those of us committed to knowledge production from a decolonizing standpoint, the challenge is to elaborate strategies of resistance to the reproduction of coloniality in our daily practice. This autoethnographic paper explores (de)coloniality from the author’s experiences in survival and resistance as she faces the precarization and privatization of academic work and the possibilities for deeply emancipatory knowledge production.
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