Correlation between T.S.P., F.S.P. and visibility in a high altitude city (Mexico City).

the metropolitan area of Mexico City is located in a high altitude basin (2 240 m above sea level) at a latitude of 19 degrees 26'13" North. It has a population of 15 million inhabitants, and the motor vehicles cruising in the city amount to 1.5 million and around 21% of the total industrial activity of the country is sited in the metropolitan area. All this activity has created an acute air pollution problem in the area which, as a direct result, has resulted in decreased visibility and possible health effects.

[Physico-chemical characteristics of different types of vegetable fats and oils used in the manufacture of candies]. / Características físico-químicas de diferentes tipos de grasas y aceites vegetales utilizados en la elaboración de bombones.

The quality of three vegetable fats (cocoa butter and two commercial fats) and three roasted nut oils (almond, hazelnut and peanut) used as raw material in the chocolate products manufacturing was studied. The hydroperoxide content, oxidative stability and fatty acid composition were determined and its health repercussion by atherogenicity and thrombogenicity indexes. Two commercial fats and cocoa butter showed higher oxidative stability, atherogenic and thrombogenic properties than oils because of its different fatty acid profiles. Peroxide value was a low reliability parameter of raw material shelf live. Rancimat presented a good correlation with the unsaturation index of different fats and oils, it was a better index than peroxide value. In the chocolate products manufacturing it would be advisable a good raw material selection and formulation in order to get a balance between technological properties, organoleptic qualities and the influence on the health. Those raw material with less primary oxidation and higher oxidative stability were also those of higher atherogenicity and thrombogenicity indexes.

[Effect on viscosity and yield value of addition of different vegetable fat sources used in chocolate]. / Repercusión sobre la viscosidad y el límite de deslizamiento de la adición de diferentes grasas vegetales a rellenos de bombones.

Viscosity and Yield Value of Casson are two chocolate properties. They are very important in the technological processes and they affect to the final product acepptation. In this study viscosity, yield value and fatty acid composition were determined of chocolates elaborated with different fat sources. A correlation study was made between these three variables. Viscosity and yield value were calculated with the Casson's education using a viscometer brookfield and fatty acids composition by gas-chromatography. Positive correlations between viscosity and yield value with stearic and palmitic acids contents have been found. Negative correlations between yield value and lauric content and viscosity and oleic acid content have been observed. The viscosity variations were relationed with total content of cocoa butter of different chocolates.

Study of the regional air quality south of Mexico City (Morelos state).

Results from the first study of the regional air quality in Morelos state (located south of Mexico City) are presented. Criteria pollutants concentrations were measured at several sites within Morelos in February and March of 2007 and 2009; meteorological data was also collected along the state for the same time periods; additionally, a coupled meteorology-chemistry model (Mesoscale Climate Chemistry Model, MCCM) was used to gain understanding on the atmospheric processes occurring in the region. In general, concentrations of almost all the monitored pollutants (O(3), NO(x), CO, SO(2), PM) remained below the Mexican air quality standards during the campaign; however, relatively high concentrations of ozone (8-hour average concentrations above the 60 ppb level several times during the campaigns, i.e. exceeding the World Health Organization and the European Union maximum levels) were observed even at sites with very low reported local emissions. In fact, there is evidence that a large percentage of Morelos vegetation was probably exposed to unhealthy ozone levels (estimated AOT40 levels above the 3 ppm h critical limit). The MCCM qualitatively reproduced ozone daily variations in the sites with an urban component; though it consistently overestimated the ozone concentration in all the sites in Morelos. This is probably because the lack of an updated and detailed emission inventory for the state. The main wind patterns in the region corresponded to the mountain-valley system (downslope flows at night and during the first hours of the day, and upslope flows in the afternoon). At times, Morelos was affected by emissions from surrounding states (Distrito Federal or Puebla). The results are indicative of an efficient transport of ozone and its precursors at a regional level. They also suggest that the state is divided in two atmospheric basins by the Sierras de Tepoztlán, Texcal and Monte Negro.