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Search Results: 1 - 10 of 44457 matches for " Sergio Natan González-Rocha "
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Circulation-Type Classification over Mexico by the Era-Interim Database and Cost733  [PDF]
Sergio Natan González-Rocha, Juan Cervantes-Pérez, Fredy Juárez-Pérez, Z. Arturo González-Cerezo, Lizeth Ríos Velasco, Inés Palomino-Méndez, José María Baldasano Recio
Atmospheric and Climate Sciences (ACS) , 2018, DOI: 10.4236/acs.2018.82019
Abstract: In this paper an approach of a synoptic classification by cluster k-means (CKM) and the European Großwettertypes (GWT) was performed and executed in COST733 package. The methodology used a CKM with nine clusters and GWT with 16. The COST733 evaluated a dataset of 30-years since 1986 to 2015. The variables selected were mean sea level pressure (mslp), geopotential height (z500 and z850), wind speed and direction (u10, v10 and u, v at 850 hPa) and relative vorticity (vo) with a 0.75° × 0.75° resolution of the data grid at 00:00, 06:00, 12:00 and 18:00 UTC and 0 steps. These results were evaluated using COST733 to find the quality of measurements by the explained variance (EV) or reduction ratio in error and pseudo F value (PF) to determine the certainty of the results. GWT-16 showed better yearly values in the evaluation with 32.7 (EV) and 354.3 (PF) against the CKM-9 of 54.2 (EV) and 1621.8 (PF). Finally, it was concluded that GWT-16 could be used for classification of synoptic systems over Mexico and the analysis of meteorological phenomena triggers on increases or decreases of atmospheric pollution in areas over Mexico.
Resultados de la simulación de gasificación del coque de petróleo mexicano de las refinerías de Ciudad Madero y Cadereyta
González-Rocha, J.C;Longoria-Ramírez, R;Urquiza-Beltrán, G;
Ingeniería, investigación y tecnología , 2008,
Abstract: this paper evaluates in terms of energy the gasification of the petroleum coke from the refineries of cd madero and cadereyta in mexico. the energy evaluation of the synthetic gas (syngas) focuses mainly on the chemical composition of the clean syngas (gasl) and its energy characteristics: heating value, the energy power, the cold gas efficiency and the thermal efficiency of gasification. the results of the simulation indicate that the gasification of the petroleum coke from cadereyta called crc, produces a gasl with better performance and energy characteristics than those obtained when gasifying the coke of petroleum from cd. madero, called crm. when the crc is gasified, the rate of production of gasl obtained is of 2.07 kggasl/kgcoque, while the rate of production of gasl for the crm is 1.89 kggasl/kgcoque. the hhv of the gasl of the crc is 12 729.56 kj/kggasl while for the crm is 11 639.13 kj/kggasl. the energy power of the gasl of the crc is greater, with a difference of 25.87 gj/h, with regard to the energy power of the gasl of the crm. under the specified conditions of operation, energy is generated ata rate of 26.46 mj/kgcoque coke in the gasification of the crc coke of petroleum, while when gasifying the crm coke of petroleum 22.09 mj/kgcoque are generated. currently, the petroleum coke produced in the refinery of madero is consumed in the power plants of tamuín, san luis potosí, mexico, while the petroleum coke produced by the refinery of cadereyta is used in the cement industry.
Estudio paramétrico de la gasificación del coque de petróleo mexicano: efecto de la alimentación de coque de petróleo sobre las características energéticas del gas sintético (gassin)
González-Rocha, J.C.;Urquiza-Beltrán, G;Longoria-Ramírez, R;
Ingeniería, investigación y tecnología , 2011,
Abstract: in this work, a parametric study the gasification of the mexican petroleum coke from the refineries of cd madero (crm) and cadereyta, nuevo león (crc) is performed. it is evaluates the energy behavior of the gasification process with objective to research which feedstock of petroleum coke has a better yield of energy. effect feed petroleum coke on energy characteristics of the clear synthetic gas (gasl): molar composition of co and h2, high heating value (hhvgasl), energy power (ωgasl),cold gas efficiency (cgegasl) and thermal efficiency of gasification (ηtg) is realized. the parametric study has been realized for 0.64 < oxygen/coke < 1.11 ratio with the flow of oxygen (6036.388 kg/h) and steam/oxygen of 23% both constant. it is observed that in oxygen/coke 0.77 and 0.94 ratio it is present the best energy characteristics of the gasl from crm and crc, respectively. the best energy characteristics relationship of the gasl fined are: molar composition co (65.6, 68.5), h2 (32.29, 29.13), hhvgasl (14054.6 kj/kggasl, 13438.76 kj/kggj, ωgasl (204.86 gj/h, 178.02 gj/h), cgegasl (74.43%, 71.14%), ηtg (86.2%, 83.22%). the gasification of petroleum coke crm produced energy with 26.20 mj/kgcoque rates whereas that gasification of the petroleum coke crc produced 27.74 mj/kgcoque rates.
Parametric Study of Gasification of the Mexican Petroleum Coke: Effect Feed Petroleum Coke on Energetic Characteristic of the Synthetic Gas (syngas)
González-Rocha J.C.,Urquiza-Beltrán G.,Longoria-Ramírez R.
Ingeniería, investigación y tecnología , 2011,
Abstract: In this work, a parametric study the gasification of the Mexican petroleum coke from the refineries of Cd Madero (CRM) and Cadereyta, Nuevo León (CRC) is performed. It is evaluates the energy behavior of the gasification process with objective to research which feedstock of petroleum coke has a be?? er yield of energy. Effect feed petroleum coke on energy characteristics of the clear synthetic gas (gasl): molar composition of CO and H2, High Heating Value (HHVgasl), energy power (Ogasl), Cold Gas Efficiency (CGEgasl) and thermal efficiency of gasification (?tg) is realized. The parametric study has been realized for 0.64 = oxygen/coke = 1.11 ratio with the fl ow of oxygen (6036.388 kg/h) and steam/oxygen of 23% both constant. It is observed that in oxygen/coke 0.77 and 0.94 ratio it is present the best energy characteristics of the gasl from CRM and CRC, respectively. The best energy characteristics relationship of the gasl fined are: molar composition CO (65.6, 68.5), H2 (32.29, 29.13), HHVgasl (14054.6 kJ/kggasl, 13438.76 kJ/kggasl), Ogasl (204.86 GJ/h, 178.02 GJ/h), CGEgasl (74.43%, 71.14%), ?tg (86.2%, 83.22%). The gasification of petroleum coke CRM produced energy with 26.20 MJ/kgcoque rates whereas that gasification of the petroleum coke CRC produced 27.74 MJ/kgcoque rates.
Air Quality Trends in Metropolitan Zones in Veracruz, México  [PDF]
Sergio Natan González Rocha, Juan Cervantes Pérez, José M. Baldasano Recio
Open Journal of Air Pollution (OJAP) , 2016, DOI: 10.4236/ojap.2016.52007
Abstract: Mexico and currently in Veracruz state, there are metropolitan zones (MZ) growing. Therefore, main objective in this paper is to analyze new data and AQ trends during 01.09.2013 to 30.06.2015 of two new AQ monitoring stations installed in Xalapa and Minatitlan MZ in 2013-year. The methodology applied used quality criteria to the datasets, followed by data validation and statistics for further analysis to determine the hourly, weekly and yearly trends of NO2, O3, SO2, PM10 and PM2.5. Indicators were compared with Mexican standards, CAI-LAC report, WHO guidelines, EU and USA standards to evaluate the AQ in both sites. We observed AQ trends from moderate to bad in Xalapa and Minatitlan MZ where the PM10 and PM2.5 surpassed the WHO guidelines and Mexican standards. O3 and SO2 in Xalapa presented a quality from good to moderate and in Minatitlan sometimes were from moderate to bad. NO2 did not exceed the value limits of Mexican standards, only Xalapa has exceeded the WHO guidelines. In Minatitlan, the Mexican limits were not exceeded. Concluding, PM10 and PM2.5 concentrations were the main problem. Others pollutants that influenced the AQ were O3, NO2 and SO2 in Minatitlan MZ due probably to meteorology, site conditions, location and oil and petrochemical industries. In Xalapa, MZ NO2 and SO2 are attributed mainly to road transport.
Apendicitis del mu?ón apendicular
Berrogain,María Carolina; González,Noelia; Rocha,Silvana; Daher,Cristian; Moguillansky,Sergio;
Revista argentina de radiolog?-a , 2012,
Abstract: stump appendicitis is a rare entity characterized by inflammation of the appendiceal remanent after incomplete appendectomy. signs and symptoms do not differ from acute appendicitis. as it is not a condition usually considered as a potential differential diagnosis of acute inflammatory abdomen, it has higher risks of complications and morbidity and mortality. imaging methods are highly useful to define the diagnosis. ultrasound (us) and computed tomography (ct) show signs similar to those found in standard cases of acute appendicitis. two cases of stump appendicitis are reponed: one managed with surgical treatment and the other with medical treatment.
Spatial-Temporal Analysis of Territorial Transformations in the State of Sinaloa Mexico Using Geographic Information Systems  [PDF]
Wenseslao Plata Rocha, Gabriela Corrales Barraza, Geovanna Guadalupe Hinojoza Castro, Sergio Alberto Monjardin Armenta, Jose Carlos Beltrán González, Héctor Enrique Rodríguez Lozoya
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.82012
Abstract: In the last years the whole planet has been suffering remarkable changes, including the land use and cover, and that this is one of the many components of the global change. The present study has as main objective described the changes of land use and cover occurred in the State of Sinaloa during the period 1976-2011. For this, we used 4 maps of land use and vegetation of 1976, 1993, 2007 and 2011. This analysis was carried out applying statistical techniques and Geographic Information Systems (GIS). The methodology is based on the analysis of the cross-tabulation matrix or change matrix, from which it is possible to obtain indicators of change for each time interval analyzed (1976-1993, 1993-2007 and 2007-2011), as well as the gain and loss of each of the 10 categories contained in the maps. To raise the level of details in the analysis were studied the annual changes considering for this the intensity of the gains and annual losses. Also we elaborated graphs and maps that allow us describing and identifying the magnitude and spatial distribution of the changes. The results obtained show a deterioration in the rainforest, important changes in the irrigated and seasonal agriculture and the spatial exchanges in the forest areas, as well as a considerable increase in the urban areas.
El cantón Bolivia o central durante el ciclo de expansión del nitrato
González,Sergio;
Estudios atacame?os , 2010, DOI: 10.4067/S0718-10432010000100007
Abstract: this article establishes the importance of the central or bolivia canton during the nitrate expansion cycle (1880-1930). we define the canton concept and establish a new expansion period (1887-1920). we conclude that the central canton, in spite of its relevance in the 19th century, belonged to a late saltpeter district, antofagasta. during the first decades of the 20th century, it shifted from being the least important of the five saltpeter districts (tarapacá, tocopilla, antofagasta, aguas blancas and taltal) to being one of the most significant.
ANáLISIS DEL ITINERARIUM EGERIAE I-II
González A,Sergio;
Byzantion nea hellás , 2009, DOI: 10.4067/S0718-84712009000100006
Abstract: the aim of this article is to give an account of those features pertaining to so-called "vulgar latin" which are present in the initial section of the itinerarium egeriae. to accomplish this, a brief discussion on the appropriateness of 'vulgar latin' as a concept is presented, followed by a description of the source, the approximate date of composition, the identity of the author and the transmission of the text. finally, the linguistic analysis focuses on those features not coincident with the classical norm, which were proper of a western koiné used for communicative rather than stylistic purposes, and which foreshadow the linguistic fragmentation of a latin-speaking area into different neo-latin dialects.
Las Bellas Artes como Terapia en Aristóteles
González A,Sergio;
Byzantion nea hellás , 2010, DOI: 10.4067/S0718-84712010000100005
Abstract: from homer onwards, greek texts show abundant references to the therapeutic applications of the fine arts. the most complete system dealing with this issue in its diverse manifestations is to be found in the platonic dialogues. however, aristotle's manifold analyses are scattered and isolated. first, the view of health as harmony in aristotle's thought is expounded, then the concepts of tékhne and phrónesis are described and compared, the necessity of art to paideía is demonstrated, and finally the therapeutic use of the different arts in order to preserve or restore health is examined'm detall.
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