Sheinbaum-Pardo C.,National Autonomous University of Mexico |
Chavez-Baeza C.,Benito Juarez University
Energy Policy | Year: 2011
This paper analyzes trends in fuel economy (kilometers per liter) of new passenger vehicles in Mexico over a period of 20 years from 1988 to 2008. Results show that in this period, fuel economy of the new passenger vehicle fleet, including multipurpose vehicles (a category similar to sport utility vehicles, SUVs), increased by only 6.3%. A simple Laspeyres index analysis was developed to evaluate both the impact of changes in vehicle sales structure by category and the changes in fuel economy. Results show that increased sales of heavier, multipurpose vehicles in place of subcompact and compact vehicles, impacted negatively on the fleet average fuel economy. If the structure of sales had continued in the same proportions across all categories as in 1988, fuel economy would have increased by 11.0%, instead of the actual 6.3%. This result coincides with trends in other countries. The paper also presents different scenarios of passenger car fuel economy for the year 2020, and its implications for gasoline consumption and CO2 emissions. The results may influence the new passenger vehicle fuel economy standard that is currently under discussion in Mexico. © 2011 Elsevier Ltd.
Romero-Salazar C.,Benito Juarez University
Superconductor Science and Technology | Year: 2016
A critical-state model is postulated that incorporates, for the first time, the structural anisotropy and flux-line cutting effect in a type-II superconductor. The model is constructed starting from the theoretical scheme of Romero-Salazar and Prez-Rodrguez to study the anisotropy induced by flux cutting. Here, numerical calculations of the magnetic induction and static magnetization are presented for samples under an alternating magnetic field, orthogonal to a static dc-bias one. The interplay of the two anisotropies is analysed by comparing the numerical results with available experimental data for an yttrium barium copper oxide (YBCO) plate, and a vanadiumtitanium (VTi) strip, subjected to a slowly oscillating field Hy (Hz ) in the presence of a static field Hz (Hy ). © 2016 IOP Publishing Ltd Printed in the UK.
Escoto C.,Autonomous University of Mexico State |
Alvarez-Rayon G.,National Autonomous University of Mexico |
Mancilla-Diaz J.M.,National Autonomous University of Mexico |
Camacho Ruiz E.J.,Benito Juarez University |
And 2 more authors.
Eating and Weight Disorders | Year: 2013
This study refers to the evaluation of the psychometric properties of the Drive for Muscularity Scale among Mexican population. The exploratory factor analysis was carried out with 369 university males (mean age = 20.93 years). A three-factor structure that explains 45.64 % of the variance was found for the scale: 31.10 % by attitudes (α = 0.87), 10.70 % by substance intake (α = 0.72) and 3.84 % by training adherence (α = 0.68). Only the two first sub-scales and total score (α = 0.86) offered acceptable levels of internal consistence. The confirmatory factor analysis, carried out with 200 males (mean age = 20.79 years), verified both the suitability of this factor structure and the two-factor structure proposed by McCreary et al. (Psychol Men Masc 5:49-58, 1). Drive for muscularity is important in comprehending male body image and Drive for Muscularity Scale has demonstrated to be psychometrically suitable to assess this construct in Mexican males. © 2013 Springer International Publishing Switzerland.
Chavez-Baeza C.,Benito Juarez University |
Sheinbaum-Pardo C.,National Autonomous University of Mexico
Energy | Year: 2014
This paper presents passenger road transport scenarios that may assist the MCMA (Mexico City Metropolitan Area) in achieving lower emissions in both criteria air pollutants (CO, NOx, NMVOC (non-methane volatile organic compounds), and PM10) and GHG (greenhouse gas) (CH4, N2O and CO2), while also promoting better mobility and quality of life in this region. We developed a bottom-up model to estimate the historical trends of energy demand, criteria air pollutants and GHG emissions caused by passenger vehicles circulating in the Mexico City Metropolitan Area (MCMA) in order to construct a baseline scenario and two mitigation scenarios that project their impact to 2028. Mitigation scenario "eff" considers increasing fuel efficiencies and introducing new technologies for vehicle emission controls. Mitigation scenario "BRT" considers a modal shift from private car trips to a Bus Rapid Transport system. Our results show significant reductions in air pollutants and GHG emissions. Incentives and environmental regulations are needed to enable these scenarios. © 2013 Elsevier Ltd.
Lopez-Acosta J.C.,University of Xalapas |
Lascurain M.,Institute Ecologia |
Lopez Binnquist C.,University of Xalapas |
Covarrubias M.,Benito Juarez University
Economic Botany | Year: 2014
Structure and Floristic Composition of Forest Management Systems Associated with the Edible Fruit Tree Oecopetalum mexicanum in the Sierra de Misantla, Veracruz, Mexico: Natural system management that favors one or a group of plant species for the benefit of humankind is one of the main factors promoting landscape change. However, depending on the focal species, management practices can promote plant diversity and contribute to the subsistence of local human populations. In this study, we identify and describe three management systems (conserved forest [CF], shade-grown coffee plantation [SGC], and enriched forest [EF]) associated with the edible fruit Oecopetalum mexicanum (Icacinaceae). The study area is in an anthropized landscape in Sierra de Misantla in central Veracruz, Mexico, where this species is of particular economic and cultural value. Three questions were addressed: 1) What is the structure and floristic diversity in each of the three identified management systems? 2) How do the management practices affect the floristic regeneration potential? and 3) How do the management systems differ in relation to the number of useful native or introduced species? In each management system, we quantified the diversity, structure, composition, physiognomy, and presence of useful species. The diversity metrics reveal a gradient in which CF is the most diverse system, followed by EF and SGC. This was observed in the groups of adult plants and in those undergoing regeneration. The EF presented the highest number of useful plants. In CF, and particularly in EF, we found a high frequency and abundance of O. mexicanum seedlings as a result of management practices that favor the germination and growth of this species. In addition, CF and EF presented analogous physiognomic characteristics. Our study demonstrates the manner in which applied management practices can determine floristic diversity, in this case reducing diversity while increasing the proportion of useful species. Furthermore, the results show that the application of management practices, especially those related to key species, can promote the conservation of natural landscape and cultural components that are of importance to the subsistence of local human populations. © 2014 The New York Botanical Garden.