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Sample records for analog chihuahua mexico

  1. U-Series Disequilibria in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s a maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include 210Pb, 234U, 230Th, 226Ra, 214Pb, and 214Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include 230Th/234U, which is greater than unity, 226Ra/230Th, which is also greater than unity, and 210Pb/214Bi, which is less than unity. The gamma-ray spectrum for organic material lacks 230Th peaks, but contains 234U and 226Ra, indicating that plants preferentially incorporate 226Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only to a few thousand years. The contribution of this study is that the short residence time of the

  2. U-Sries Disequilibra in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    D. French; E. Anthony; P. Goodell

    2006-03-16

    The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s a maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include {sup 210}Pb, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, and {sup 214}Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include {sup 230}Th/{sup 234}U, which is greater than unity, {sup 226}Ra/{sup 230}Th, which is also greater than unity, and {sup 210}Pb/{sup 214}Bi, which is less than unity. The gamma-ray spectrum for organic material lacks {sup 230}Th peaks, but contains {sup 234}U and {sup 226}Ra, indicating that plants preferentially incorporate {sup 226}Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only

  3. GAMMA-RAY CHARACTERIZATION OF THE U-SERIES INTERMEDIATE DAUGHTERS FROM SOIL SAMPLES AT THE PENA BLANCA NATURAL ANALOG, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    D.C. French; E.Y. Anthony; P.C. Goodell

    2005-07-18

    The Pena Blanca natural analog is located in the Sierra Pena Blanca, approximately 50 miles north of Chihuahua City, Mexico. The Sierra Pena Blanca is composed mainly of ash-flow tuffs, and the uranium in the region is contained in the brecciated zones of these tuffs. The Pena Blanca site is considered a natural analog to the proposed Yucca Mountain Nuclear Waste Repository because they share similar characteristics of structure, volcanic lithology, tectonic activity, and hydrologic regime. One of the mineralized zones, the Nopal I deposit, was mined in the early 1980s and the ore was stockpiled close to the mine. This stockpile area has subsequently been cleared and is referred to as the prior high-grade stockpile (PHGS) site. Soil surrounding boulders of high-grade ore associated with the PHGS site have been sampled. The purpose of this study is to characterize the transport of uranium series radioisotopes from the boulder to the soil during the past 25 years. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. The daughter to parent ratios are used to establish whether the samples are in secular equilibrium. Activities are determined using gamma-ray spectroscopy. Isotopes of the uranium series decay chain detected by gamma-ray spectroscopy include {sup 210}Pb, {sup 234}U, {sup 234}Th, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, {sup 214}Bi, and {sup 234}Pa. Preliminary results indicate that some daughter to parent pairs appear to be in secular disequilibrium. Thorium is in excess relative to uranium, and radium is in excess relative to thorium. A deficiency appears to exist for {sup 210}Pb relative to {sup 214}Bi and {sup 214}Pb. If these results are borne out by further analysis, they would suggest transport of nuclides from the high-grade boulder into its surroundings, followed by continued leaching of uranium and lead from the environment.

  4. Unsaturated zone waters from the Nopal I natural analog, Chihuahua, Mexico -- Implications for radionuclide mobility at Yucca Mountain

    International Nuclear Information System (INIS)

    Chemical and U-Th isotopic data on unsaturated zone waters from the Nopal I natural analog reveal effects of water-rock interaction and help constrain models of radionuclide release and transport at the site and, by analogy, at the proposed nuclear waste repository at Yucca Mountain. Geochemical reaction-path modeling indicates that, under oxidizing conditions, dissolution of uraninite (spent fuel analog) by these waters will lead to eventual schoepite precipitation regardless of initial silica concentration provided that groundwater is not continuously replenished. Thus, less soluble uranyl silicates may not dominate the initial alteration assemblage and keep dissolved U concentrations low. Uranium-series activity ratios are consistent with models of U transport at the site and display varying degrees of leaching versus recoil mobilization. Thorium concentrations may reflect the importance of colloidal transport of low-solubility radionuclides in the unsaturated zone

  5. Unsaturated zone waters from the Nopal I natural analog, Chihuahua, Mexico -- Implications for radionuclide mobility at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, D.A.; Murphy, W.M.

    1999-07-01

    Chemical and U-Th isotopic data on unsaturated zone waters from the Nopal I natural analog reveal effects of water-rock interaction and help constrain models of radionuclide release and transport at the site and, by analogy, at the proposed nuclear waste repository at Yucca Mountain. Geochemical reaction-path modeling indicates that, under oxidizing conditions, dissolution of uraninite (spent fuel analog) by these waters will lead to eventual schoepite precipitation regardless of initial silica concentration provided that groundwater is not continuously replenished. Thus, less soluble uranyl silicates may not dominate the initial alteration assemblage and keep dissolved U concentrations low. Uranium-series activity ratios are consistent with models of U transport at the site and display varying degrees of leaching versus recoil mobilization. Thorium concentrations may reflect the importance of colloidal transport of low-solubility radionuclides in the unsaturated zone.

  6. THE U.S./MEXICO WATER DISPUTE: IMPACTS OF INCREASED IRRIGATION IN CHIHUAHUA, MEXICO

    OpenAIRE

    Rosson, C. Parr, III; Hobbs, Aaron; Adcock, Flynn J.

    2003-01-01

    The U.S./Mexico Water Dispute: Impacts of Increased Irrigation in Chihuahua, Mexico. C. Parr Rosson, III, Texas A&M University, Aaron Hobbs, Texas A&M University, and Flynn Adcock, Texas A&M University. Mexico accumulated a water debt of 1.5 million acre feet to the United States while increasing its use of irrigation water by fourteen percent in Chihuahua. This paper documents recent trends in irrigated production of major crops grown in Chihuahua, estimates irrigation water use in Chihuahua...

  7. Short-Term Water Dynamics in Chihuahua City, Mexico

    OpenAIRE

    Thomas M Fullerton Jr; Ana Cecilia Nava

    2004-01-01

    Linear transfer ARIMA analysis of monthly per meter water consumption is conducted for Chihuahua City, Mexico. Sample data from January 1988 to December 2000 are analyzed. Time series utilized include water system revenue, climate, and industrial production data. Out-of-sample simulations are used to confirm the reliability of the in-sample estimation results.

  8. Energy saving programs and renewable energies in Chihuahua, Mexico; Programas de ahorro de energia y energias renovables en Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra Noris, Jose Luis [Gobierno del Estado de Chihuahua (Mexico)

    2005-07-01

    The high index of economic and technological growth registered in the border zone of northern Mexico in the last years, has simultaneously caused an annual growth in the electrical energy demand in a percentage higher than 6%. In this document are included the economic and environmental impacts caused by the projects developed in the Chihuahua State on energy efficiency and on the available potential of renewable energies. In order to evaluate the environmental impact that is caused when saving electrical energy in the diverse projects in process, the emission of CO{sub 2} is the only emission taken into account (even though also emissions of SO{sub 2}, NO{sub 2} and Hg exist) for being this polluting agent the one that contributes in greater amount to the global warming and the greenhouse effect. The emission index of CO{sub 2} that we considered in this presentation is of 600 kg/mwh, on the basis of the type of fuel and volume of generation of the plants in operation of the Comision Federal de Electricidad (CFE) in the Chihuahua State. [Spanish] El alto indice de crecimiento economico y tecnologico registrado en la zona fronteriza del norte de Mexico en los ultimos anos, ha ocasionado paralelamente un crecimiento en la demanda de energia electrica superior al 6% anual. En este documento se incluyen los impactos economicos y ambientales de los proyectos que se desarrollan en el estado de Chihuahua en eficiencia energetica y en el potencial que se tiene de energias renovables. Para evaluar el impacto ambiental que se obtiene al ahorrar energia electrica en los diversos proyectos en proceso, se toma en cuenta unicamente emisiones de CO{sub 2} (aun cuando tambien existen emisiones de SO{sub 2}, NO{sub 2} y Hg) por ser este el contaminante que en mayor cantidad afecta al calentamiento global y al efecto invernadero. El indice de emisiones de CO{sub 2} que consideramos en esta presentacion es de 600 kg/mwh, en base al tipo de combustible y volumen de generacion de las

  9. Wind Transport of Radionuclide- Bearing Dust, Peña Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Velarde, R.; Goodell, P. C.; Gill, T. E.; Arimoto, R.

    2007-05-01

    This investigation evaluates radionuclide fractionation during wind erosion of high-grade uranium ore storage piles at Peña Blanca (50km north of Chihuahua City), Chihuahua, Mexico. The aridity of the local environment promotes dust resuspension by high winds. Although active operations ceased in 1983, the Peña Blanca mining district is one of Mexico`s most important uranium ore reserves. The study site contains piles of high grade ore, left loose on the surface, and separated by the specific deposits from which they were derived (Margaritas, Nopal I, and Puerto I). Similar locations do not exist in the United States, since uranium mining sites in the USA have been reclaimed. The Peña Blanca site serves as an analog for the Yucca Mountain project. Dust deposition is collected at Peña Blanca with BSNE sediment catchers (Fryrear, 1986) and marble dust traps (Reheis, 1999). These devices capture windblown sediment; subsequently, the sample data will help quantify potentially radioactive short term field sediment loss from the repository surface and determine sediment flux. Aerosols and surface materials will be analyzed and radioactivity levels established utilizing techniques such as gamma spectroscopy. As a result, we will be able to estimate how much radionuclide contaminated dust is being transported or attached geochemically to fine grain soils or minerals (e.g., clays or iron oxides). The high-grade uranium-bearing material is at secular equilibrium, thus the entire decay series is present. Of resulting interest is not only the aeolian transport of uranium, but also of the other daughter products. These studies will improve our understanding of geochemical cycling of radionuclides with respect to sources, transport, and deposition. The results may also have important implications for the geosciences and homeland security, and potential applications to public health. Funding for this project is provided in part via a NSF grant to Arimoto.

  10. Paleotectonic controls on deposition of upper Upper Jurassic La Casita Formation, east-central Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.C.

    1989-03-01

    Surface mapping of the basal Mesozoic La Casita Formation (upper Upper Jurassic) in east-central Chihuahua, Mexico, indicates initial Mesozoic sedimentation occurred in a segmented, interconnected subbasin of the Chihuahua trough. La Casite Formation (1200 m thick) is a tectonostratigraphic unit resting with angular unconformity on the Lower Permian Plomosas Formation. It consists primarily of siliciclastic material with sporadic interbedded limestones. The dominant lithofacies, approximately 1000 m thick, consists of turbiditic sandstone units (10-20 m) alternating with thicker, monotonous shale sequences. In the mapped area (approximately 30 km/sup 2/), flute cast measurements indicate flows from both the northeast (N20/degree/E) and southwest (S58/degree/W). Turbiditic sandstone units appear to pinch out and/or interfinger as they extend from the north and south into the central portion of the area. The initial opening of the Chihuahua trough is often associated with Late Jurassic block faulting, related to development of the ancestral Gulf of Mexico. Synrift depositional sequences of a similar age have been described in southern Coahuila, northern Zacatecas, and western Chiapas, Mexico. The subbasin (graben ) examined here may be ascribed a paleoposition near the western edge of the early Chihuahua trough. The western boundary of the early trough may have comprised a series of these subbasins, forming a cuspate or serrated coastline. Late Jurassic ammonites recovered from this and other localities along the length of the Chihuahua trough suggest that the subbasins were interconnected by means of an eastern continuous seaway.

  11. Characterization of urban solid waste in Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The characterization of urban solid waste generation is fundamental for adequate decision making in the management strategy of urban solid waste in a city. The objective of this study is to characterize the waste generated in the households of Chihuahua city, and to compare the results obtained in areas of the city with three different socioeconomic levels. In order to identify the different socioeconomic trends in waste generation and characterization, 560 samples of solid waste were collected during 1 week from 80 households in Chihuahua and were hand sorted and classified into 15 weighted fractions. The average waste generation in Chihuahua calculated in this study was 0.676 kg per capita per day in April 2006. The main fractions were: organic (48%), paper (16%) and plastic (12%). Results show an increased waste generation associated with the socioeconomic level. The characterization in amount and composition of urban waste is the first step needed for the successful implementation of an integral waste management system

  12. Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

    International Nuclear Information System (INIS)

    The Chihuahua Basin is divided by its morphology into three main sub basins: Chihuahua-Sacramento sub basin, Chihuahua Dam sub basin and Chuviscar River sub basin. In the aquifers at the Sacramento sub basin, specific concentrations of uranium in groundwater range from 460 to 1260 Bq / m3. The presence of strata and sandy clay lenses with radiometric anomalies in the N W of Chihuahua Valley was confirmed by a litostatigraphic study and gamma spectrometry measurements of drill cuttings. High uranium activity values found in the water of some deep wells may correspond to the presence of fine material bodies of carbonaceous material, possible forming pa leo-sediment of flooding or pa leo-soils. It is suggested that these clay horizons are uranyl ion collectors. Uranyl may suffer a reduction process by organic material. Furthermore the groundwater, depending on its ph and Eh, oxidizes and re-dissolves uranium. The hydrogeochemical behavior of San Marcos dam and the N W Valley area is the subject of studies that should help to clarify the origin of the radioactive elements and their relationships with other pollutants in the watershed. (Author)

  13. Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Burillo, J. C.; Reyes C, M.; Montero C, M. E.; Renteria V, M.; Herrera P, E. F. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes No. 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Reyes, I.; Espino, M. S., E-mail: elena.montero@cimav.edu.mx [Universidad Autonoma de Chihuahua, Facultad de Ingenieria, Nuevo Campus Universitario, Chihuahua (Mexico)

    2012-06-15

    The Chihuahua Basin is divided by its morphology into three main sub basins: Chihuahua-Sacramento sub basin, Chihuahua Dam sub basin and Chuviscar River sub basin. In the aquifers at the Sacramento sub basin, specific concentrations of uranium in groundwater range from 460 to 1260 Bq / m{sup 3}. The presence of strata and sandy clay lenses with radiometric anomalies in the N W of Chihuahua Valley was confirmed by a litostatigraphic study and gamma spectrometry measurements of drill cuttings. High uranium activity values found in the water of some deep wells may correspond to the presence of fine material bodies of carbonaceous material, possible forming pa leo-sediment of flooding or pa leo-soils. It is suggested that these clay horizons are uranyl ion collectors. Uranyl may suffer a reduction process by organic material. Furthermore the groundwater, depending on its ph and Eh, oxidizes and re-dissolves uranium. The hydrogeochemical behavior of San Marcos dam and the N W Valley area is the subject of studies that should help to clarify the origin of the radioactive elements and their relationships with other pollutants in the watershed. (Author)

  14. Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

    Directory of Open Access Journals (Sweden)

    J.C. Burillo

    2012-01-01

    Full Text Available La cuenca hidrológica de Chihuahua se divide por su geomorfología en tres principales subcuencas: Subcuenca Chihuahua-Sacramento, Subcuenca de la presa Chihuahua y Subcuenca del río Chuv´ícar. En los acuíferos de la subcuenca Sacramento, las concentraciones especí¿ficas del uranio en agua subterránea fluctúan de 460 a 1260 Bq/m3. Se comprobó la localización de estratos y lentes arcillo-arenosos con anomalías radiométricas en la zona NW del valle Chihuahua, mediante un estudio litoestatigráfico de barrenos y por mediciones de espectrometría gamma. Las anomalías encontradas en el agua de algunos pozos profundos se corresponden con la presencia de cuerpos de material fino areno-arcillosos mezclado con material carbonoso, formando posibles paleo-suelos o paleo-sedimentos de inundación. Se sugiere que estos horizontes areno-arcillosos son recolectores del ion uranilo y hacen que el uranilo sufra un proceso de reducción por el material orgánico. Después el agua subterránea, en dependencia del pH y el Eh, oxida nuevamente y redisuelve el uranio, pasando al agua que se extrae de los pozos. La hidrogeoquímica de la presa de San Marcos y de la zona NW del valle es objeto de estudios que deben contribuir a esclarecer el origen de los elementos radiactivos y sus relaciones con otros contaminantes en la cuenca.

  15. Geologic studies in the Sierra de Pena Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Reyes-Cortes, Ignacio Alfonso

    The Sierra del Cuervo has been endowed with uranium mineralization, which has attracted many geological studies, and recently the author was part of a team with the goal of selecting a site of a radioactive waste repository. The first part of the work adds to the regional framework of stratigraphy and tectonics of the area. It includes the idea of a pull apart basin development, which justifies the local great thickness of the Cuervo Formation. It includes the regional structural frame work and the composite stratigraphic column of the Chihuahua Trough and the equivalent Cretaceous Mexican Sea. The general geologic features of the NE part of the Sierra del Cuervo are described, which include the folded ignimbrites and limestones in that area; the irregular large thicknesses of the Cuervo Formation; and the western vergence of the main folding within the area. Sanidine phenocrystals gave ages of 54.2 Ma and 51.8 Ma ± 2.3 Ma. This is the first time these dates have been reported in print. This age indicates a time before the folded structures which outcrop in the area, and 44 Ma is a date after the Cuervo Formation was folded. The Hidalgoan orogeny cycle affected the rocks between this lapse of time. Since then the area has been partially affected by three tensional overlapped stages, which resulted in the actual Basin and Range physiography. The jarosite related to the tectonic activity mineralization has been dated by the Ar-Ar method and yields an age of 9.8 Ma. This is the first report of a date of mineralization timing at Pena Blanca Uranium District in the Sierra del Cuervo. These are some of the frame work features that justify the allocation of a radioactive waste repository in the Sierra del Cuervo. An alluvial fan system within the Boquilla Colorada microbasin was selected as the best target for more detailed site assessment. The study also included the measurement of the alluvium thicknesses by geoelectric soundings; studies of petrography and weathered

  16. Natural Analog Studies at Pena Blanca, Mexico

    International Nuclear Information System (INIS)

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment

  17. Natural Analog Studies at Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Simmons

    2005-07-11

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment.

  18. Uranium-series isotopes transport in surface, vadose and ground waters at San Marcos uranium bearing basin, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    In the U deposit area at San Marcos in Chihuahua, Mexico, hydrogeological and climatic conditions are very similar to the Nopal I, Peña Blanca U deposit, 50 km away. The physicochemical parameters and activity concentrations of several 238U-series isotopes have been determined in surface, vadose and ground waters at San Marcos. The application of some published models to activity ratios of these isotopes has allowed assessing the order of magnitude of transport parameters in the area. Resulting retardation factors in San Marcos area are Rf238 ≈ 250–14,000 for the unsaturated zone and ≈110–1100 for the saturated zone. The results confirm that the mobility of U in San Marcos is also similar to that of the Nopal I U deposit and this area can be considered as a natural analog of areas suitable for geologic repositories of high-level nuclear waste.

  19. Radioactive mineral samples from the northwest of Chihuahua City, Mexico

    International Nuclear Information System (INIS)

    The Chihuahua-Sacramento valley is an area of 6 km wide by about 32 km in length, it is located from north to south. In the area, at least two zones exist that may have rocks with radioactive minerals: The Pastorias zone at the SW and the Majalca-San Marcos zone to the NW. The latter, was the object of the present investigation. By studying the geologic conditions and the processes of alteration in the San Marcos deposits, its hydrothermal origin and the different (at least two) alteration stages that has transformed the alkaline rhyolitic rock into per-alkaline were determined, to do more favorable the conditions for the hexavalent uranium minerals deposits. In the mineralogical characterization the following radioactive species were identified: uranofane, meta tyuyamunite and uraninite. These minerals were found also with secondary quartz-feldspar mineralization, with abundant hematization and an advanced process of argillization. The XRD, SEM and optical microscopy analyses of samples were very important for the accomplishment of the present investigation. (Author)

  20. Bio-climatic strategy for energy saving in corporative buildings. City Juarez, Chihuahua, Mexico; Estrategia bioclimatica para ahorro energetico en edificios corporativos. Ciudad Juarez, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Staines Orozco, E. R.

    2008-07-01

    Ciudad Juarez Chihuahua in Mexico is located in of de biggest Desert of Arid America called Chihuahuan Desert, and is there in where this border city with United State of North America and one of the border cities of greater commercial importance (a million six hundred thousands pop. approx.) has been develop to great influence of wasteful constructive systems of nonrenewable resources as they are the gas and electricity. These building take back surpassed models. In this article presents a design of a model of corporative building of five floors that counts including all a strategy from the process of architectonic design to the applications of echo passive and active Technologies (hybrid) like one of a ventilation tower, strategy that applied guarantees the significant saving to use energy. (Author)

  1. Neotropical River Otter Micro-Habitat Preference In West-Central Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Carrillo-Rubio E.

    2004-07-01

    Full Text Available We characterised habitat selected by the Neotropical otter (Lontra longicaudis in the Río San Pedro, located in the central portion of the State of Chihuahua in Northern Mexico. We monitored a 30 km stretch of the river for over two years and compared micro-site habitat characteristics at 21 used and 25 random sites. Characteristics of habitat preferred by the otter included pools that averaged >0.8 m deep, >14.6 m wide, >64% under-story vegetation cover, and rock talus/vegetation cover within 4.8 m.

  2. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    This paper reports 222Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited 222Rn concentrations exceeding 11 Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of 222Rn found may be entirely attributed to the nature of aquifer rocks

  3. Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

    Science.gov (United States)

    Ochoa-Martinez, Angeles C; Orta-Garcia, Sandra T; Rico-Escobar, Edna M; Carrizales-Yañez, Leticia; Del Campo, Jorge D Martin; Pruneda-Alvarez, Lucia G; Ruiz-Vera, Tania; Gonzalez-Palomo, Ana K; Piña-Lopez, Iris G; Torres-Dosal, Arturo; Pérez-Maldonado, Ivan N

    2016-05-01

    It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (Ciudad Juarez is necessary. PMID:26987540

  4. Uranium in the Surrounding of San Marcos-Sacramento River Environment (Chihuahua, Mexico)

    Science.gov (United States)

    Rentería-Villalobos, Marusia; Cortés, Manuel Reyes; Mantero, Juan; Manjón, Guillermo; García-Tenorio, Rafael; Herrera, Eduardo; Montero-Cabrera, Maria Elena

    2012-01-01

    The main interest of this study is to assess whether uranium deposits located in the San Marcos outcrops (NW of Chihuahua City, Mexico) could be considered as a source of U-isotopes in its surrounding environment. Uranium activity concentrations were determined in biota, ground, and surface water by either alpha or liquid scintillation spectrometries. Major ions were analyzed by ICP-OES in surface water and its suspended matter. For determining uranium activity in biota, samples were divided in parts. The results have shown a possible lixiviation and infiltration of uranium from geological substrate into the ground and surface water, and consequently, a transfer to biota. Calculated annual effective doses by ingestion suggest that U-isotopes in biota could not negligibly contribute to the neighboring population dose. By all these considerations, it is concluded that in this zone there is natural enhancement of uranium in all environmental samples analyzed in the present work. PMID:22536148

  5. Characterization of drought patterns through remote sensing over The Chihuahua Desert, Mexico"

    Science.gov (United States)

    Madrigal, J. M.; Lopez, A.; Garatuza, J.

    2013-12-01

    Drought is a phenomenon that has intensified during the last few decades in the arid and semi-arid zones of northern Mexico. In the Chihuahua desert, across Chihuahua, Durango and Coahuila states has caused loss of food sustainability (agriculture, livestock), an increase in human health problems, and detriment of ecosystem services as well as important economic losses. In order to understand this phenomenon, it is necessary to create tools that allow monitoring the territory's spatial heterogeneity and multi-temporality. With this purpose we propose the implementation of a drought model which includes the traditional indexes of climatic drought, such as the Palmer Drought Severity Index PDSI, the Standardized Index of Rainfall SPI, data from meteorological stations and biophysical variations obtained from the MODIS sensors product MOD13 NDVI from 2001 to 2010, as well as biophysical variables characteristic of the environment, such as land use and vegetation coverage, Eco-regions, soil moisture, digital elevation model and irrigate agriculture districts. With the MODIS images, a spatially coherent time series was created analyzing the study area's phenology (TIMESAT) created the Seasonal Greenness (SG) and Start of Season Anomaly (SOSA) for the mentioned nine years. Through this, the annual cycles were established. With a decision tree model, all the previously mentioned proposed variables were integrated. The proposed model produces a general map which characterizes the vegetation condition (extreme drought, severe drought, moderate drought, near normal). Even though different techniques have been proposed on the monitoring of droughts, most of them generate drought indexes with a spatial resolution of 1km (Wardlow, B. et. al 2008; Levent T. et al. 2013). One of the main concerns of researchers on the matter is on improving the spatial information content and on having a better representation of the phenomenon. We use the normalized difference vegetation index

  6. Geometry of the El Fresnal basin, northern Chihuahua, Mexico, as inferred from three-dimensional gravity modeling (parte A)

    OpenAIRE

    W. L. Bandy; J. Ortega Ramírez; J. M. Maillol; A. Valiente Banuet; Rodríguez, J. A.

    2002-01-01

    A multidisciplinary study of the El Fresnal basin, Chihuahua, Mexico is being conducted to investigate the relationships between the structure, vegetation and geomorphology and the Quaternary paleoenvironment. As part of this study, 221 new gravity measurements were collected within the basin and combined with 506 preexisting measurements from the surrounding area to determine the basin geometry and the depth of the sediment infill. A basement-depth model calculated from these data indicates ...

  7. PBDEs, PCBs, and DDE in eggs and their impacts on aplomado falcons (Falco femoralis) from Chihuahua and Veracruz, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mora, M.A., E-mail: mmora@tamu.edu [Department of Wildlife and Fisheries Sciences, Texas A and M University, College Station, TX 77843-2258 (United States); Baxter, C. [Department of Wildlife and Fisheries Sciences, Texas A and M University, College Station, TX 77843-2258 (United States); Sericano, J.L. [Geochemical and Environmental Research Group, Texas A and M University, College Station, TX 77845 (United States); Montoya, A.B. [The Peregrine Fund, Inc, Boise, ID 83709 (United States); Gallardo, J.C. [Instituto de Neuroetologia, Universidad Veracruzana, Xalapa, Veracruz 91190 (Mexico); Rodriguez-Salazar, J.R. [The Peregrine Fund, Inc, Boise, ID 83709 (United States)

    2011-12-15

    Eggs from aplomado falcons (Falco femoralis septentrionalis) nesting in Chihuahua and Veracruz, Mexico, were analyzed for organochlorine pesticides, PCBs, and PBDEs. p,p'-DDE was the only organochlorine found in all eggs at concentrations ranging from 0.13 to 7.85 {mu}g/g wet weight. PCBs ranged from 0.04 to 2.80 {mu}g/g wet weight and PBDEs from 62 to 798 ng/g lipid weight. DDE concentrations in eggs were not significantly different among regions; however, PCBs were significantly greater (P = 0.015) in Tinaja Verde, Chihuahua than in the other three regions. Also, PBDEs were significantly higher (P < 0.0001) in eggs from Veracruz than in those from Chihuahua. DDE concentrations in eggs were much lower than those associated with eggshell thinning. PBDEs and PCBs were lower than those reported in raptors from industrialized countries. Overall, contaminant concentrations observed suggest no likely impact on hatching success. The PBDE concentrations are among the first to be reported in raptor species in Mexico. - Highlights: > We analyzed environmental contaminants in eggs of aplomado falcons from Mexico. > Of all the organochlorine pesticides, only p,p'-DDE was detected in all the eggs. > Eggshell thickness was 20% thicker than the reported in eggshells from the 1970s. > Total PCBs and PBDEs were lower than those reported in industrialized countries. > Aplomado falcons in Mexico are currently not affected by DDE, PCBs, or PBDEs. - PBDEs, PCBs, and p,p'-DDE were not elevated in eggs and not likely to impact aplomado falcons in eastern and northern Mexico.

  8. Establishment of Native Grasses with Biosolids on Abandoned Croplands in Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Pedro Jurado-Guerra

    2013-01-01

    Full Text Available The objective of the work was to evaluate establishment and forage production of native grasses with application of biosolids, a byproduct of waste-water treatment, at an abandoned field, in Ejido Nuevo Delicias, Chihuahua, Mexico. Four biosolids rates from 0 (control to 30 dry Mg ha−1 and two methods of application, surface applied (BioSur and soil incorporated (BioInc, were evaluated. Seedbed preparation included plowing and harrowing before rainfall. Field plots of 5 × 5 m were manually sown with a mix of blue grama (Bouteloua gracilis (50% and green sprangletop (Leptochloa dubia (50% in early August 2005. Experimental design was a randomized block with a split plot arrangement. Grass density, height, and forage production were estimated for three years. Data were analyzed with mixed linear models and repeated measures. Green sprangletop density increased under all biosolids rates regardless of method of application, while blue grama density slightly decreased. Biosolids were more beneficial for green sprangletop height than for blue grama height. Blue grama forage production slightly increased, while green sprangletop forage production increased the most at 10 Mg ha−1 biosolids rate under BioSur method. It was concluded that BioSur application at 10 and 20 Mg ha−1 rates had positive effects on the establishment and forage production of native grasses, especially green sprangletop.

  9. Uranium deposits associated to tertiary acid volcanism of the Pena Blanca Sierra (Chihuahua, Mexico)

    International Nuclear Information System (INIS)

    The uraniferous deposits located in the Sierra de Pena Blanca (Chihuahua, Mexico) are the consequence of successive events that modified acid volcanic rocks. The devitrification of the Nopal Formation, vitroclastic tuffs, is esential in the cooling history because it releases uranium that becomes available. The uranium present in fluids as uranylcarbonate complexes, precipitate along the lamellea of hematite (exsolutions of the ilmenites). The presence of sulfur causes the destabilization of the ilmenites with uranium oxide (pitchblende - titanium oxide - pyrite), the pseudomorph of magnetites (pitchblende - pyrite) and the transformation of hematite into pyrite. The silice coming from the kaolinization of feldspars recristallizes as microcristalline quartz so that the rock appears compact. Fractures cause the uplifting of the lower unit of Nopal formation. It has been altered to montmorillonite. A carbonatation of this tuff has been observed and these two types of alteration occur after kaolinization. The Escuadra formation overlies the Nopal formation. The deposition takes place on an eroded basement where a soil developed. The two formations will together undergo transformations due to the saturation level and the primary ore will be only oxidized or oxidized, transported and reconcentrated. Late and localized thermal activities have been observed and may be the result of tectonic movements occurring after the supergene modification

  10. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times observed for the front adit area. Seepage data obtained from this study will be used to provide input to flow and transport models being developed for the Nopal I hydrogeologic system.

  11. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    Science.gov (United States)

    Dobson, Patrick F.; Ghezzehei, Teamrat A.; Cook, Paul J.; Rodríguez-Pineda, J. Alfredo; Villalba, Lourdes; de La Garza, Rodrigo

    2012-02-01

    A study of seepage occurring in an adit at the Nopal I uranium mine in Chihuahua, Mexico, was conducted as part of an integrated natural analogue study to evaluate the effects of infiltration and seepage on the mobilization and transport of radionuclides. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage. Field observations recorded between April 2005 and December 2006 indicate that seepage is highly heterogeneous with respect to time, location, and quantity. Seepage, precipitation, and fracture data were used to test two hypotheses: (1) that fast flow seepage is triggered by large precipitation events, and (2) that an increased abundance of fractures and/or fracture intersections leads to higher seepage volumes. A few zones in the back adit recorded elevated seepage volumes immediately following large (>20 mm/day) precipitation events, with transit times of less than 4 h through the 8-m thick rock mass. In most locations, there is a 1-6 month time lag between the onset of the rainy season and seepage, with longer times observed for the front adit. There is a less clear-cut relation between fracture abundance and seepage volume; processes such as evaporation and surface flow along the ceiling may also influence seepage.

  12. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat A.; Rodriguez, J. Alfredo; Villalba, Lourdes; de la Garza, Rodrigo

    2008-10-25

    An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times observed for the front adit area. Seepage data obtained from this study will be used to provide input to flow and transport models being developed for the Nopal I hydrogeologic system.

  13. Migration behavior of naturally occurring radionuclides at the Nopal I uranium deposit, Chihuahua, Mexico

    Science.gov (United States)

    Prikryl, James D.; Pickett, David A.; Murphy, William M.; Pearcy, English C.

    1997-04-01

    Oxidation of pyrite at the Nopal I uranium deposit, Peña Blanca district, Chihuahua, Mexico has resulted in the formation of Fe-oxides/hydroxides. Anomalous U concentrations (i.e. several hundred to several thousand ppm) measured in goethite, hematite, and amorphous Fe-oxyhydroxides in a major fracture that crosscuts the deposit and the absence of U minerals in the fracture suggest that U was retained during secondary mineral growth or sorbed on mineral surfaces. Mobilization and transport of U away from the deposit is suggested by decreasing U concentrations in fracture-infilling materials and in goethite and hematite with distance from the deposit. Greater than unity {234U}/{238U} activity ratios measured in fracture-infilling materials indicate relatively recent ( < 1 Ma) U uptake from fluids that carried excess 234U. Systematic decreases in {234U}/{238U} activity ratios of fracture materials with distance from the deposit suggest a multistage mobilization process, such as remobilization of U from 234U-enriched infill minerals or differential or diminished transport of U-bearing solutions containing excess 234U.

  14. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232Th-series, 238U-series, 40K and 137Cs activity concentrations (AC, Bq kg−1) were determined by gamma spectrometry with a high purity Ge detector. 238U and 234U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210Pb activities. Results were verified by 137Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234U/238U and 238U/226Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232Th/238U, 228Ra/226Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs

  15. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Rodriguez-Pineda; P. Goodell; P.F. Dobson; J. Walton; R. Oliver; De La Garza; S. Harder

    2005-07-11

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area.

  16. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area

  17. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Méndez-García, C.; Montero-Cabrera, M. E., E-mail: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, CIMAV, Miguel de Cervantes 120, 31109, Chihuahua, Chihuahua (Mexico); Renteria-Villalobos, M. [Facultad de Zootecnia y Ecología Universidad Autónoma de Chihuahua, Periferico Francisco R. Almada Km 1, 31410, Chihuahua (Mexico); García-Tenorio, R. [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2008-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. ²³²Th-series, ²³⁸U-series, ⁴⁰K and ¹³⁷Cs activity concentrations (AC, Bq kg⁻¹) were determined by gamma spectrometry with a high purity Ge detector. ²³⁸U and ²³⁴U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to ²¹⁰Pb activities. Results were verified by ¹³⁷Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High ²³⁸U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) ²³⁴U/²³⁸U and ²³⁸U/²²⁶Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. ²³²Th/²³⁸U, ²²⁸Ra/²²⁶Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  18. Geochemical and isotopic features of groundwater in the Villa Ahumada-Samalayuca region, state of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The Villa Ahumada - Samalayuca region is located in the Basins and Ranges Province of the Chihuahua State, Mexico, Its climate is arid and semidesertic, with a mean annual precipitation of 258 mm. The geology is characterized by the presence of sandstones, shales and limestones, from Cretassic-Jurassic; there exists a composition of gravel, sand, silt, clay and gypsum, from Terciary-Quaternary. The major ionic chemical data indicate that the groundwater flow, in the region, is S-NW direction; the content of stable isotopes from the shallow and deep groundwater is homogeneous, which supports the existence of one aquifer system, with a recharge from a common origin. 17 refs, 7 figs, 2 tabs

  19. Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

    International Nuclear Information System (INIS)

    Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th, 40K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h-1. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg-1, of 226Ra, 232Th and 40K, respectively. From the analysis of the spatial distribution of 232Th, 226Ra, and 40K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

  20. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Directory of Open Access Journals (Sweden)

    Sergio Luevano-Gurrola

    2015-09-01

    Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  1. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-01-01

    Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

  2. Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M. [Universidad Autonoma de Chihuahua, Facultad de Zootecnia y Ecologia, Perif. Francisco R. Almada Km 1, 31415 Chihuahua, Chih. (Mexico); Carrillo F, J.; Montero C, M. E., E-mail: mrenteria@uach.mx [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Chih. (Mexico)

    2015-10-15

    Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of {sup 226}Ra, {sup 232}Th, {sup 40}K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h{sup -1}. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg{sup -1}, of {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. From the analysis of the spatial distribution of {sup 232}Th, {sup 226}Ra, and {sup 40}K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

  3. Seasonal characterization of municipal solid waste (MSW) in the city of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Management of municipal solid waste (MSW) has become a significant environmental problem, especially in fast-growing cities. The amount of waste generated increases each year and this makes it difficult to create solutions which due to the increase in waste generation year after year and having to identify a solution that will have minimum impact on the environment. To determine the most sustainable waste management strategy for Chihuahua, it is first necessary to identify the nature and composition of the city's urban waste. The MSW composition varied considerably depending on many factors, the time of year is one of them. Therefore, as part of our attempt to implement an integral waste management system in the city of Chihuahua, we conducted a study of the characteristics of MSW composition for the different seasons. This paper analyzes and compares the findings of the study of the characterization and the generation of solid waste from households at three different socio-economic levels in the city over three periods (April and August, 2006 and January, 2007). The average weight of waste generated in Chihuahua, taking into account all three seasons, was 0.592 kg capita-1 day-1. Our results show that the lowest income groups generated the least amount of waste. We also found that less waste was generated during the winter season. The breakdown for the composition of the waste shows that organic waste accounts for the largest proportion (45%), followed by paper (17%) and others (16%).

  4. Seasonal characterization of municipal solid waste (MSW) in the city of Chihuahua, Mexico.

    Science.gov (United States)

    Gómez, Guadalupe; Meneses, Montserrat; Ballinas, Lourdes; Castells, Francesc

    2009-07-01

    Management of municipal solid waste (MSW) has become a significant environmental problem, especially in fast-growing cities. The amount of waste generated increases each year and this makes it difficult to create solutions which due to the increase in waste generation year after year and having to identify a solution that will have minimum impact on the environment. To determine the most sustainable waste management strategy for Chihuahua, it is first necessary to identify the nature and composition of the city's urban waste. The MSW composition varied considerably depending on many factors, the time of year is one of them. Therefore, as part of our attempt to implement an integral waste management system in the city of Chihuahua, we conducted a study of the characteristics of MSW composition for the different seasons. This paper analyzes and compares the findings of the study of the characterization and the generation of solid waste from households at three different socio-economic levels in the city over three periods (April and August, 2006 and January, 2007). The average weight of waste generated in Chihuahua, taking into account all three seasons, was 0.592 kg capita(-1) day(-1). Our results show that the lowest income groups generated the least amount of waste. We also found that less waste was generated during the winter season. The breakdown for the composition of the waste shows that organic waste accounts for the largest proportion (45%), followed by paper (17%) and others (16%). PMID:19303762

  5. Modeling of U-series Radionuclide Transport Through Soil at Pena Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Pekar, K. E.; Goodell, P. C.; Walton, J. C.; Anthony, E. Y.; Ren, M.

    2007-05-01

    The Nopal I uranium deposit is located at Pena Blanca in Chihuahua, Mexico. Mining of high-grade uranium ore occurred in the early 1980s, with the ore stockpiled nearby. The stockpile was mostly cleared in the 1990s; however, some of the high-grade boulders have remained there, creating localized sources of radioactivity for a period of 25-30 years. This provides a unique opportunity to study radionuclide transport, because the study area did not have any uranium contamination predating the stockpile in the 1980s. One high-grade boulder was selected for study based upon its shape, location, and high activity. The presumed drip-line off of the boulder was marked, samples from the boulder surface were taken, and then the boulder was moved several feet away. Soil samples were taken from directly beneath the boulder, around the drip-line, and down slope. Eight of these samples were collected in a vertical profile directly beneath the boulder. Visible flakes of boulder material were removed from the surficial soil samples, because they would have higher concentrations of U-series radionuclides and cause the activities in the soil samples to be excessively high. The vertical sampling profile used 2-inch thicknesses for each sample. The soil samples were packaged into thin plastic containers to minimize the attenuation and to standardize sample geometry, and then they were analyzed by gamma-ray spectroscopy with a Ge(Li) detector for Th-234, Pa-234, U-234, Th-230, Ra-226, Pb-214, Bi-214, and Pb-210. The raw counts were corrected for self-attenuation and normalized using BL-5, a uranium standard from Beaverlodge, Saskatchewan. BL-5 allowed the counts obtained on the Ge(Li) to be referenced to a known concentration or activity, which was then applied to the soil unknowns for a reliable calculation of their concentrations. Gamma ray spectra of five soil samples from the vertical profile exhibit decreasing activities with increasing depth for the selected radionuclides

  6. Creación de la Biblioteca Virtual Ambiental del Estado de Chihuahua en El Colegio de Chihuahua

    OpenAIRE

    Cervantes-Rendón, Esmeralda

    2008-01-01

    Presentation that talks about the thesis of the same title (Creation of the Environmental Virtual Library in the Mexican Chihuahua State at the Colegio de Chihuahua) at the Master Program in Environmental Engineering at the Ciudad Juarez Autonomous University, Chihuahua, Mexico.

  7. Experience in the transport and disposal of uranium mill tailings from Aldama City to Sierra Pena Blanca in Chihuahua, Mexico

    International Nuclear Information System (INIS)

    In the process of decontamination, transport and disposal of uranium mill tailings, in the state of Chihuahua, Mexico, was necessary the multidisciplinary and multi institutional task to select mainly the site for the final disposal. The uranium mill tailings content Ra-226 which half live time is 1600 years, therefore the site should be adequately stable, a remote place of population, and which containment will survive for thousand of years. The decontamination of site where the uranium mill tailings were 25 years ago, required the application of norms from regulator organism. For the transport of uranium mill tailings was necessary that the vehicles had devices to reduce the dispersion of material in the road. The selection of the site was product of balance between the cost of transport and the final disposal. To typify the site, studies of hydrology, meteorology, ecology, geology and seismology were performed. On the other hand, the decision to locate the deposit in the site was due to dispersion of material by the rain, wind and bowls. (authors). 3 refs., 1 fig., 1 tab

  8. Variation in the distribution of four cacti species due to climate change in Chihuahua, Mexico.

    Science.gov (United States)

    Cortes, Leonor; Domínguez, Irma; Lebgue, Toutcha; Viramontes, Oscar; Melgoza, Alicia; Pinedo, Carmelo; Camarillo, Javier

    2014-01-01

    This study is about four cacti species in the state of Chihuahua, (Coryphantha macromeris, Mammillaria lasiacantha, Echinocereus dasyacanthus and Ferocactus wislizenii). Geographic distribution was inferred with MaxEnt. Projection was estimated under three scenarios simulated from IPCC (A2, B1 and A1B) and four periods (2000, 2020, 2050 and 2080) with 19 climatic variables. MaxEnt projects a species decrease in 2020 under scenario A2, increasing in the following years. In 2080 all species, except E. dasyacanthus, will occupy a larger area than their current one. Scenario B1 projected for 2050 a decrease for all species, and in 2080 all species except E. dasyacanthus will increase their area. With A1B, C. macromeris decreases 27% from 2020 to 2050. E. dasyacanthus increases from 2020 to 2050 and decreases 73% from 2020 to 2080. M. lasiacantha decreases 13% from 2020 to 2080 and F. wislizenii will increase 13% from 2020 to 2080. Some species will remain stable on their areas despite climate changes, and other species may be affected under the conditions of the A1B scenario. It is important to continue with studies which give a broader perspective about the consequences of climate change, thus enabling decision-making about resource management. PMID:24368429

  9. Variation in the Distribution of Four Cacti Species Due to Climate Change in Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Leonor Cortes

    2013-12-01

    Full Text Available This study is about four cacti species in the state of Chihuahua, (Coryphantha macromeris, Mammillaria lasiacantha, Echinocereus dasyacanthus and Ferocactus wislizenii. Geographic distribution was inferred with MaxEnt. Projection was estimated under three scenarios simulated from IPCC (A2, B1 and A1B and four periods (2000, 2020, 2050 and 2080 with 19 climatic variables. MaxEnt projects a species decrease in 2020 under scenario A2, increasing in the following years. In 2080 all species, except E. dasyacanthus, will occupy a larger area than their current one. Scenario B1 projected for 2050 a decrease for all species, and in 2080 all species except E. dasyacanthus will increase their area. With A1B, C. macromeris decreases 27% from 2020 to 2050. E. dasyacanthus increases from 2020 to 2050 and decreases 73% from 2020 to 2080. M. lasiacantha decreases 13% from 2020 to 2080 and F. wislizenii will increase 13% from 2020 to 2080. Some species will remain stable on their areas despite climate changes, and other species may be affected under the conditions of the A1B scenario. It is important to continue with studies which give a broader perspective about the consequences of climate change, thus enabling decision-making about resource management.

  10. Natural radioactivity in groundwater and estimates of committed effective dose due to water ingestion in the state of Chihuahua (Mexico)

    International Nuclear Information System (INIS)

    The activity concentration of 222Rn, 226Ra and total uranium in groundwater samples collected from wells distributed throughout the state of Chihuahua has been measured. The values obtained of total uranium activity concentration in groundwater throughout the state run from -1. Generally, radium activity concentration was -1, with some exceptions; in spring water of San Diego de Alcala, in contrast, the value reached ∼5.3 Bq l-1. Radon activity concentration obtained throughout the state was from 1.0 to 39.8 Bq l-1. A linear correlation between uranium and radon dissolved in groundwater of individual wells was observed near Chihuahua City. Committed effective dose estimates for reference individuals were performed, with results as high as 134 μSv for infants in Aldama city. In Aldama and Chihuahua cities the average and many individual wells showed activity concentration values of uranium exceeding the Mexican norm of drinking water quality. (authors)

  11. Determination of Rn222 in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico

    International Nuclear Information System (INIS)

    The study of the content of dissolved Rn222 is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn222 in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn222 in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  12. Occurrence of environmental mycobacteria in water from the central zone of the Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Environmental mycobacteria are inhabitants of many reservoirs, including water, soil, plats, animals and humans, The aquatic environment is an important reservoir of environmental mycobacteria; where their presence is influenced by biotic and abiotic factors. The presence of environmental mycobacteria in water has been related with health problems in immunosuppressed patients. In Mexico, there are not reports of the ecology of mycobacteria; therefore, the aim of this work was to characterize reservoir sites, like creeks and drinking troughs, and to determine some biotic and abiotic environmental factors to understand the conditions leading to their environmental persistence. (Author)

  13. Geospatial Mapping of Pb, Cr, Cu, Zn, Cd, and Sb in Urban Soil, Cd. Juarez, Chihuahua, Mexico

    Science.gov (United States)

    Amaya, M. A.; Grimida, S. E.; Elkekli, A. R.; Aldouri, R. K.; Benedict, B. A.; Pingitore, N. E., Jr.

    2015-12-01

    Population-based random stratified sampling of the city of Cd. Juarez, Chihuahua, Mexico provided 500 city blocks for study. We collected soil from the public space (where present) in front of each house on a selected block; equal measured small volumes of these were combined to produce a composite sample for analysis. Such composite samples (1) decrease, by an order of magnitude, laboratory processing and analysis costs, and (2) smooth the data to represent blocks as averages of individual houses. Retention of the unanalyzed samples of the individual houses permits their later analysis should the composites suggest further study of individual houses on an anomalous block. Elemental analysis of 10 mg pressed powders was performed on a Panalytical Epsilon5 EDS-XRF, via 8 secondary targets and 12 USGS and NIST multi-element rock standards. The mean and (range) of concentration for Pb was 43 (13-550) ppm; for Cr, 31 (1.8-76); for Cu, 22 (6-550); for Zn 84 (42-415) ppm; for Cd, 1.9 (0.1-6.2); and for Sb, 5.9 (2.7-29). The old urban core of Cd. Juarez was marked by high levels of Pb, Cr, Cu, and Zn, and, to a smaller degree, of Cd and Sb. This pattern mirrors that of contiguous El Paso, Texas, USA, directly across the narrow Rio Grande. Businesses, industrial facilities, transportation (both railroads and highways), traditional "downtown" shopping, and old residential districts cluster in this urban core. A Pb-Cu-Zn smelter, which operated for more than a century until 1999, is present in the US adjacent to the Rio Grande, about two km away from downtown Cd. Juarez. Thus the city has been subject to both traditional metal sources (e.g., leaded gasoline, highway debris) and smelter emissions. The poplation of Cd. Juarez has exploded in the last few decades to some 1.5 million inhabitants due both to natural growth and in-migration from rural districts for economic opportunity. Most of this growth has been accommodated by radial expansion of the city into the surrounding

  14. Evaluation of the impact of groundwater resources on surface water in Chihuahua, Northern Mexico

    International Nuclear Information System (INIS)

    We carried out a stream-aquifer interaction study in Rio Conchos basin, Northern Mexico, to find out the best water resources management strategy for the improvement and conservation of damaged aquatic ecosystems. A numerical finite-difference model (MODFLOW) was used to simulate groundwater flow of a sub-area of the Meoqui-Delicias aquifer system with a length of 40 km along the Rio Conchos and 10 km to both sides of this stream. A two-step calibration was achieved to increase the reliability of the model: the first step was the traditional process of adjusting hydraulic model parameters and comparing the results until calculated head values closely match the measured values at selected points of the upper aquifer; the second step included the comparison of results from a particle tracking program (MODPATH) with tracer data (origin and residence time of water) by using a backward particle tracking process in the numerical flow model.The results indicate that in the present study area evaporational enrichment processes from irrigation might have an impact on the estimation of residence times. (author)

  15. Lung Cancer Mortality and Radon Concentration in a Chronically Exposed Neighborhood in Chihuahua, Mexico: A Geospatial Analysis

    OpenAIRE

    Hinojosa de la Garza, Octavio R.; Sanín, Luz H.; María Elena Montero Cabrera; Korina Ivette Serrano Ramirez; Enrique Martínez Meyer; Manuel Reyes Cortés

    2014-01-01

    This study correlated lung cancer (LC) mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K) and Inverse-Distance Weighting (IDW) spatial interpolations were carried out. Deaths were georeferenced and Moran's I correlation coefficients were calculated. The mean values (o...

  16. Mexican Queso Chihuahua: functional properties of aging cheese

    Science.gov (United States)

    Queso Chihuahua, a traditional, semi-hard cheese manufactured from raw milk (RM) in northern Mexico, is being replaced by pasteurized milk (PM) versions because of food safety concerns and to extend shelf-life. In this study, the functional traits of authentic Mexican Queso Chihuahua made with RM o...

  17. Lung cancer mortality and radon concentration in a chronically exposed neighborhood in Chihuahua, Mexico: a geospatial analysis.

    Science.gov (United States)

    Hinojosa de la Garza, Octavio R; Sanín, Luz H; Montero Cabrera, María Elena; Serrano Ramirez, Korina Ivette; Martínez Meyer, Enrique; Reyes Cortés, Manuel

    2014-01-01

    This study correlated lung cancer (LC) mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K) and Inverse-Distance Weighting (IDW) spatial interpolations were carried out. Deaths were georeferenced and Moran's I correlation coefficients were calculated. The mean values (over n = 171) of the interpolation of radon concentrations of deceased's dwellings were 247.8 and 217.1 Bq/m(3), for K and IDW, respectively. Through the Moran's I values obtained, correspondingly equal to 0.56 and 0.61, it was evident that LC mortality was directly associated with locations with high levels of radon, considering a stable population for more than 25 years, suggesting spatial clustering of LC deaths due to indoor radon concentrations. PMID:25165752

  18. Lung Cancer Mortality and Radon Concentration in a Chronically Exposed Neighborhood in Chihuahua, Mexico: A Geospatial Analysis

    Directory of Open Access Journals (Sweden)

    Octavio R. Hinojosa de la Garza

    2014-01-01

    Full Text Available This study correlated lung cancer (LC mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K and Inverse-Distance Weighting (IDW spatial interpolations were carried out. Deaths were georeferenced and Moran’s I correlation coefficients were calculated. The mean values (over n=171 of the interpolation of radon concentrations of deceased’s dwellings were 247.8 and 217.1 Bq/m3, for K and IDW, respectively. Through the Moran’s I values obtained, correspondingly equal to 0.56 and 0.61, it was evident that LC mortality was directly associated with locations with high levels of radon, considering a stable population for more than 25 years, suggesting spatial clustering of LC deaths due to indoor radon concentrations.

  19. Randon emanometry in the uraniferous district of Sierra Pena Blanca and in other volcanic areas of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    There are difficulties associated with the repeatability of radon measurements using portable emanometers owing to the effects of meteorological phenomena on soil gases. The paper describes a correction method based on fluctuation curves. Orientation surveys were carried out on different days at the Las Margaritas and Nopal I deposits of the Sierra Pena Blanca and the radon concentrations measured at the same stations were found to be very different. In the surveys, fluctuation curves at stations were determined, and the readings from the surveys were subsequently corrected. The surveys performed on the first day showed no conspicuous anomalies directly above the deposits, but after correction of the measurements the anomalies increased to a factor of 3-4 above the normal concentration. The second surveys showed considerable anomalies above the deposits and also increased after correction of the measurements. The fluctuation curves obtained at the Sierra de la Gloria and other prospects of the north central part of Chihuahua showed highs in the mornings and evenings. The most common variations in the fluctuation curves are between 100% and 200%, although they can be higher. The corrections to the measured concentrations were calculated by means of straight-line graphs and also by the CORRAD program, which calculates a curve by the least squares method. Systematic surveys without any correction show strong line effects which render their use impractical. Corrections calculated with straight-line graphs reduce the line effect, while surveys corrected with the CORRAD program show a better distribution of anomalies, making them more useful. (author)

  20. Leaching Behavior of Slags from AN Old Lead Smelter in Chihuahua, Mexico: Metals, Chlorides, Nitrates, Sulfates and Tds Analyses

    Science.gov (United States)

    Espejel-Garcia, D.; Wenglas-Lara, G.; Villalobos-Aragon, A.; Espejel-Garcia, V. V.

    2013-05-01

    Waste materials (such as, smelter slags, waste glass, tires, plastics, rubbish, ashes, etc.), have a large potential to substitute natural materials, reducing costs, especially for the construction industry. Smelter slags are resistant and have better compression strength values in comparison to natural aggregates, and generally are far beyond of what the standard ratios need to qualify a material as a good one for construction. But this material has a big problem within it: the existence of toxic elements and compounds in high concentrations, which means that water and soil contamination can be present after water infiltrates through this material; so we perform leaching experiments to characterize and measure the possible contamination under controlled conditions. To perform the slags-leaching experiments, we used an EA-NEN-7375-2004 tank test standard from Netherlands. This test was selected because to our knowledge it is the only one which allows the use of coarse material, as the one utilized in construction. The leaching experiments sampling was performed at different times: 6, 24, 168 and 360 hours, to compare the leachate concentration at the two different pH's values (5 and 8) selected to simulate real conditions. For the leaching experiments, the slags were mixed with natural road base material (gravel-sands from volcanic rocks) at different proportions of 30% and 50%. In order to understand the slags' leaching behavior, other experiments were carried out with the pure material, for both (slags and natural aggregates). After analyses by ICP-OES , the slags from this smelter in Chihuahua contain Pb (0.5 - 4 wt.%), Zn (15-35 wt.%) and As (0.6 wt.%), as well such as: bicarbonates, chlorides, nitrates, sulfates, Mg, K, Na, Ca and TDS. Based on the results of the leaching analyses, via atomic absorption technique, we conclude that Pb and As concentrations are provided by the slags, meanwhile, the bicarbonates, chlorides, Na and Ca are contributed by the road

  1. Geology and geochemistry of newly discovered Tertiary carbonatite occurrences near Villa Ahumada area, Basin and Range province, Chihuahua, northern Mexico

    Science.gov (United States)

    Nandigam, Ravi Chenchu

    This study targets some newly discovered carbonatite occurrences located in the eastern Mexican Basin and Range province, a few kilometers to the east of Villa Ahumada, Chihuahua. The region containing these occurrences experienced compression related to subduction of the Farallon plate until about 32 Ma that was followed by Basin and Range extension. Geological mapping (1:5,000 scale), petrography, study of drill hole cuttings and satellite images, and major and trace element chemical analyses were utilized to understand the intrusive style of the carbonatites, their mineralogy and petrogenesis. The carbonatites, named Yuca, Mariana and El Indio, collectively intrude limestones, granitic intrusives and subduction-related tuffs and lavas mainly as a stock, breccias and dikes. The Yuca carbonatite was emplaced as a 900-m diameter stock, 500 x 350 m breccia body, numerous dikes and networks of fracture fillings. Crosscutting field relationships at Yuca suggest at least two stages of carbonatite emplacement. At Mariana, carbonatite was emplaced as a 750 x 350 m breccia. Four out of nine reverse circulation drill holes penetrated and bottomed in the breccia at an average depth of about 300 m At El Indio, carbonatite was emplaced as a 20 m diameter breccia pipe and a 1m thick sill. Major minerals present are calcite, Fe-rich calcite and hematite. Sporadic presence of fluorite is common. At Mariana, two generations of grossular-rich garnets associated with limestones and granite porphyry respectively are recognized. It is inferred that garnets in granite porphyry represent metasomatic alteration due to the emplacement of carbonatite breccia. Parental magmas of Yuca carbonatites have undergone differentiation under low fO2 conditions during which they were progressively enriched in iron. The carbonatite compositional types recognized based on major element data, in the sequence of least to most highly differentiated, are (1) magnesio-, (2) calcio- and (3

  2. Aspects of radiological safety and protection in the decontamination of the Benefit plant of uranium in Ciudad Aldama and in the storage of its residues in Pena Blanca, Chihuahua, Mexico; Aspectos de seguridad y proteccion radiologica en la descontaminacion de la planta de beneficio de uranio en Ciudad Aldama y en el almacenamiento de sus residuos en Pena Blanca, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz C, M.A. [Facultad de Quimica, UNAM (Mexico)

    1998-07-01

    Between 1969 and 1971 the National Commission of Nuclear Energy and the Mining Fostering Commission operated coordinately a production plant of uranium and molybdenum concentrates (Benefit plant) at Ciudad Aldama, Chihuahua, Mexico. During two years of operation some 45 tonnes of uranium concentrate and approximately 35,000 tonnes of uranium wetlands were produced. These last were stored in a dam to 120 m. toward West of the plant. Due to the nearness of the population with respect to what was the Benefit plant and over all to the wetland dam, the objective of this work had two main aspects: On the one hand, to carry out the works of radiological decontamination of the benefit plant of uranium, according to the established normative by the Regulatory organization in matter of radiological safety and protection (CNSNS) for the population and the hard workers. After that the works mentioned were realized it was considered that the estate which comprises what was the Benefit plant did not reach the established criteria by the CNSNS for being considered of unrestricted use such estate and it was not allowed any type of construction in the zone which could be showed the residual contamination which remains there. On the other hand, to determine the site where could be stored the radioactive wastes generated by the radiological decontamination and the wetland mobilization for its definitive storage in benefit of the present population and of the future generations due to the radionuclides which are in a such material. The site more adequate technical and economically to storage the wastes generated by this activity was evaluated. Whereby studies about demography, use of soil and water, meteorology, hydrology and ecology were realized. The site selected being in the Pena Blanca mountains, Chihuahua, place where is located one of the uranium zones and the most important of the country. In this work, specific objectives also were treated such as: knowing the radiological

  3. Integrated petrographic and geochemical study of coal and gas shales from the Sabinas and Chihuahua basins, North of Mexico: estimation of methane gas resources

    International Nuclear Information System (INIS)

    This comprehensive characterization study was performed using organic petrology and geochemistry conducted in the Sabinas basin and Chihuahua in northern Mexico. This information allowed a numerical modeling of gas formation, considering the thermal subsidence of coal and carbonaceous shales. The objectives of this thesis are: - Establish a characterization methodology for the studied rocks - Estimate potential gas generator and its regional distribution - Estimate the methane gas resources For the development of this project, we conducted an intensive campaign representative sampling of coal, carbonaceous shales and coal gas 'in situ'. For the Sabinas basin were studied 97 samples and 114 samples in the basin of Chihuahua. The analyses carried out that were used on the samples analyzed allowed to characterize the kerogen and gas. The methodology used to cross petrographic and geochemical information to analyze the petroleum system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6R (Bulk rock), isotopic analysis, δ13C, δD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions. The analyzes that were used on the samples allowed to characterize the sample, the kerogen and gas. The methodology used to cross petrographic and geochemical information for analyze the oil system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6R (Bulk rock), isotopic analysis, δ13C, δD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions A computer program was constructed to cross the information with the analysis of samples of artificial maturation experiments in the laboratory. This approach allowed estimation of methane gas resources generated by coal and carbonaceous shales. The main results obtained for Sabinas Basin were: - The kerogen of the organic

  4. Health impacts of air pollution on morbidity and mortality among children of Ciudad Juarez, Chihuahua, Mexico : working paper

    International Nuclear Information System (INIS)

    This study evaluated the impact of air pollution on a group of children in Ciudad Juarez, Mexico where a large urban population of children live in poor conditions. In particular, the study examined the associations between ozone ambient levels and respiratory-related emergency visits to hospitals by children. The impact of PM10 on respiratory health was also examined. Upper respiratory infections and asthma were found to be associated with ozone ambient levels for all age groups. In children aged 5 or less, ozone exposure was related to lower respiratory infections as well. Ambient air pollutants were not related to respiratory deaths in the population of children involved in this study, but data suggests that that PM10 ambient levels might increase the risk of respiratory mortality in infants less than one year old. An increase in respiratory mortality was noted among infants from the lowest socio-economic status (SES) group. This report emphasizes the need for implementing cost effective interventions to control existing air pollution problems and to prevent the situation from worsening. 22 refs., 27 tabs., 5 figs

  5. Niveles ambientales de las PM2.5 y distancia a una vía de alto tránsito en Ciudad Juárez, Chihuahua, México Environmental PM2.5 levels and distance from a heavy traffic road in Ciudad Juarez, Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Marlene Cortez-Lugo

    2004-12-01

    Full Text Available OBJETIVO: Evaluar los niveles de las PM2.5 a diferentes distancias de una vía de alto tránsito. MATERIAL Y MÉTODOS: Se realizaron mediciones diarias de PM2.5, del 26 al 30 de agosto de 2002, a diferentes distancias de la avenida Tecnológico, en Ciudad Juárez, Chihuahua, México. Se hizo estadística descriptiva para cada distancia considerada y análisis de las pruebas no paramédicas de Kruskal Wallis y de tendencias cruzadas en grupos ordenados. RESULTADOS: Se encontró una tendencia de decremento significativa de la mediana de las PM2.5 conforme se aleja el punto de medición de la avenida Tecnológico (pOBJECTIVE: To assess PM2.5 levels at different distances from a heavy traffic road. MATERIAL AND METHODS: Daily measurements of PM2.5 were taken between August 26 and 30, 2002, at different distances from Tecnológico Avenue in Ciudad Juarez, Chihuahua, Mexico. Data analysis consisted of descriptive statistics for each distance and Kruskal Wallis and cross trend for ranks. RESULTS: We found a significantly decreasing trend of PM2.5 median levels with increasing distance from Tecnológico Avenue (p< 0.001. At 100 m distance from the avenue, PM2.5 levels decreased by 9.5 µg/m3 (40.6% when compared to median levels registered on the avenue. The results showed a highly significant negative correlation between PM2.5 measurements and the distance from the avenue (r=-0.70, n=20 and p=0.0005. CONCLUSIONS: PM2.5 median levels decreased significantly after 100 meters from heavy traffic roads. These results are of great relevance when assessing exposure to PM2.5 in epidemiological studies.

  6. Historic and Current Distributions of River Otters (Lontra canadensis and (Lontra longicaudis in the Río Grande or Río Bravo del Norte Drainage of Colorado and New Mexico, USA and of Chihuahua, Mexico and Adjacent Areas

    Directory of Open Access Journals (Sweden)

    Paul Polechla

    2009-10-01

    Full Text Available The Río Grande drainage is an important and imperiled wetland of the US/Mexican border arid lands. There is a desire to restore otter populations in this river by interested parties. In order to follow IUCN guidelines for restoration, biologists need learn more fully the situation prior to implementation of restoration management. A prerequisite for proper restoration conservation is to know the organism’s taxonomy (i.e., what taxa or species and subspecies one is dealing with, distribution, and relative abundance. The historic and current distribution of the Nearctic otter (Lontra canadensis and Neotropical otter (L. longicaudis in the borderlands of US and Mexico are reviewed in this paper. The evidence indicates that otters were native to the Río Grande valley and has been recorded in the languages and customs of Native Americans such as the Pueblo people prior to European settlement of the area. The first Spanish documents we were able to find whereby otters were recorded, date to the middle 16th century. Otters during historical times were probably more numerous than previously thought and one of the first wildlife laws in the borderlands revolved around a moratorium on trapping the otter and beaver. Presently, populations of otters occur in 1 the Río San Pedro of Chihuahua, a tributary of the Río Conchos entering the Río Grande from the southeast, 2 the upper Río Grande near the Colorado/New Mexico border, and 3 the middle Pecos River in southeastern New Mexico entering the Río Grande from the west. These observations are corroborated by multiple observations by competent observers and in the case of the first population, otter photos and sign. These populations are centered on areas with macro-habitats characterized by a river flowing through 1 deep canyons, or 2 ancillary wetlands. Considerable more detailed survey work is needed to determine the full extent of the distribution of otters in the Río Grande drainage. A genetic

  7. Determination of Rn{sup 222} in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico; Determinacion de Rn{sup 222} en muestras de agua de pozos y domicilio de las ciudades de Chihuahua y Aldama, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L.; Colmenero S, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: lourdes.villalba@cimav. edu. mx

    2004-07-01

    The study of the content of dissolved Rn{sup 222} is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn{sup 222} in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn{sup 222} in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  8. Comentarios a la tesis en curso de la maestría en ingeniería ambiental de la Universidad Autónoma de Ciudad Juárez (UACJ) que elabora la Ing. Quím. Esmeralda Cervantes Rendón para la Creación de la Biblioteca Virtual Ambiental de Chihuahua en el Colegio de Chihuahua, en Ciudad Juárez, Chihuahua, México

    OpenAIRE

    Muela-Meza, Zapopan Martín

    2007-01-01

    This document includes through 14 pages the main comments made by the author to the ongoing thesis of the Environmental Engineering Master Degree program at the Ciudad Juarez Autonomous University (UACJ) being conducted by Ms. Esmeralda Cervantes Rendon, undergraduate in Chemical Engineering for the Creation of a Virtual [sic] Environmental Library of the Mexican state of Chihuahua at the College of Chihuahua Research Centre in Ciudad Juarez, Chihuahua, Mexico which belongs to the nationwide ...

  9. Aspects of radiological safety and protection in the decontamination of the Benefit plant of uranium in Ciudad Aldama and in the storage of its residues in Pena Blanca, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Between 1969 and 1971 the National Commission of Nuclear Energy and the Mining Fostering Commission operated coordinately a production plant of uranium and molybdenum concentrates (Benefit plant) at Ciudad Aldama, Chihuahua, Mexico. During two years of operation some 45 tonnes of uranium concentrate and approximately 35,000 tonnes of uranium wetlands were produced. These last were stored in a dam to 120 m. toward West of the plant. Due to the nearness of the population with respect to what was the Benefit plant and over all to the wetland dam, the objective of this work had two main aspects: On the one hand, to carry out the works of radiological decontamination of the benefit plant of uranium, according to the established normative by the Regulatory organization in matter of radiological safety and protection (CNSNS) for the population and the hard workers. After that the works mentioned were realized it was considered that the estate which comprises what was the Benefit plant did not reach the established criteria by the CNSNS for being considered of unrestricted use such estate and it was not allowed any type of construction in the zone which could be showed the residual contamination which remains there. On the other hand, to determine the site where could be stored the radioactive wastes generated by the radiological decontamination and the wetland mobilization for its definitive storage in benefit of the present population and of the future generations due to the radionuclides which are in a such material. The site more adequate technical and economically to storage the wastes generated by this activity was evaluated. Whereby studies about demography, use of soil and water, meteorology, hydrology and ecology were realized. The site selected being in the Pena Blanca mountains, Chihuahua, place where is located one of the uranium zones and the most important of the country. In this work, specific objectives also were treated such as: knowing the radiological

  10. Estudio de Factibilidad para la puesta en marcha de los Digestores Anaerobicos en Establos Lecheros en la Cuenca de Delicias, Chihuahua, Mexico

    OpenAIRE

    Casas Prieto, Miguel Angel; Rivas Lucero, Bertha Alicia; Soto Zapata, Manuel; Segovia Lerma, Armando; Morales Morales, Hugo Armando; Cuevas Gonzalez, Martha Isela; Kiessling Davison, Christian Mauricio

    2009-01-01

    The energetic value as end product is among several benefits from effective waste management programs at intensive feedlots. It is increasing around the world since organic waste is a source of environmental pollution. The biogas can be obtained from simple to complex scale anaerobic digesters. Currently, there is in Mexico official instruments supporting clean technologies to promote the sustainable developing at regional levels. Based on Kyoto Protocol principles, Mexico has been promoting ...

  11. Characterization of uranium minerals from Chihuahua using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Burciaga V, D. C.; Reyes C, M.; Reyes R, A.; Renteria V, M.; Esparza P, H.; Fuentes C, L.; Fuentes M, L; Silva S, M.; Herrera P, E.; Munoz, A.; Montero C, M. E. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua (Mexico)

    2010-02-15

    Uranium mineral deposits in the vicinity of Chihuahua City (northern Mexico) have motivated a multidisciplinary investigation due to their tech no-environmental importance. It provides a broad scope study of representative mineral samples extracted from the San Marcos deposit, located northwest of Chihuahua City. The zone of interest is the source of the Sacramento River, which runs at Chihuahua City. The high uranium content of the San Marcos deposit, which was formed by hydrothermal mineralization, has resulted in elevated levels of uranium in surface and ground water, fish, plants and sediments in this region. Mineral identification of the uranium-bearing phases was accomplished with a suite of techniques. Among these phases are those called meta tyuyamunite (Ca(UO{sub 2}){sub 2}(VO{sub 4}){sub 2{center_dot}}3-5 H{sub 2}O) and becquerelite [Ca(UO{sub 2}){sub 6}O{sub 4}(OH){sub 6{center_dot}}8(H{sub 2}O)]. It was decided to study an almost pure meta tyuyamunite sample extracted from Pena Blanca, Chihuahua uranium ore and to synthesize the becquerelite, using a modified procedure from a published one. In the current work the crystal structure of meta tyuyamunite is presented, resolved by the Rietveld refinement. Both samples were studied by X-ray absorption fine structure at beamline 2-3, Stanford Synchrotron Radiation Light source. In the present work both the spectra and extended X-ray absorption fine structure parameters are presented. (Author)

  12. Calculation of the structural shielding of the radiotherapy treatment room equipped with a linear accelerator type Tomo therapy Hi-Art in the Oncology Center of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    . In this work these specific methodologies are used for the structural shielding calculations of the tomo therapy equipment installed in the Oncology Center of Chihuahua. These calculation methodologies consider the primary radiation, of leakage, disperse, second dispersion and leakage dispersion. The obtained results indicate that due to the lead barrier of the primary beam, the main component that contributes to the shielding requirements of the installation is the leakage radiation. On the other hand, the component that more affects of the door shielding is the dispersion component in the patient. (Author)

  13. Ni una más. International cooperation against gender-based discrimination: the femicide case in Ciudad Juárez, Chihuahua, Mexico

    OpenAIRE

    Torres Trucios, Elvia Ernestina

    2008-01-01

    The femicide in Ciudad Juárez is a story made of extreme violence against women for different reasons, by different actors, under different circumstances, and following different behavioural patterns. All within a gender discrimination frame based on the idea that women are inferior, interchangeable and disposable according to the patriarchal hierarchy still present in Mexico, but strongly reinforced by a sort of conspiracy of silence provoked either by the high impunity rate, the...

  14. Morbilidad infantil por causas respiratorias y su relación con la contaminación atmosférica en Ciudad Juárez, Chihuahua, México Infant morbidity caused by respiratory diseases and its relation with the air pollution in Juarez City, Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Leticia Hernández-Cadena

    2007-02-01

    de control de la contaminación atmosférica para evitar que empeore la situación actual.OBJECTIVE: To assess the impact of atmospheric pollutants on the respiratory health of children of different age groups in Juarez City, Chihuahua, Mexico. MATERIAL AND METHODS: Data on emergency room visits between 1997 and 2001 for respiratory diseases in children less than 17 years old were obtained from hospitals in the Juarez City belonging to the Mexican Social Security Institute (IMSS. Diseases were classified into three groups according to ICD 9th and 10th codes: a upper respiratory diseases, b lower respiratory diseases, and c asthma attacks. This information was stratified by age group (5 years. Daily air pollution data (ozone and PM10 and weather conditions were obtained from the Monitoring Network System in Juarez City. Statistical analysis was carried out using a Generalized Additive Model assuming a Poisson distribution. RESULTS: Ozone concentrations, but not PM10, were statistically associated with emergency room visits for respiratory diseases, mainly among children 5 years old or younger. In this group, an increase of 20 ppb 1-hr maximum for ozone was associated with an increase of 8.3% in the number of emergency room visits for upper respiratory diseases, with a 3-day exposure lag; and an increase of 12.7% in the number of emergency room visits for lower respiratory diseases when considering a 4-day exposure lag in a maximum 8-hr mobile average. The largest effect for the complete sample and for the group 6 to 16 years of age was observed for 3-day lag (5.1% for an increase of 20 ppb 1-hr maximum for ozone. For the 6 to16 year old group we did not find a significant effect. CONCLUSION: The wide range of risk is quite important and might represent a substantial cost for the health system as well as for the society. Our results emphasize the need to implement preventive and control measures for air pollution and avoid the worsening of the present situation.

  15. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    International Nuclear Information System (INIS)

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal

  16. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Simmons; M. T. Murrell

    2001-05-31

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal.

  17. Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juarez, Chihuahua (Mexico)

    International Nuclear Information System (INIS)

    Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO2) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.-Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO2 appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children's exposures to these pollutants vary based on the location of their school. - Highlights: → First binational investigation characterizing traffic air pollutants at four schools in El Paso, USA and Cd. Juarez, Mexico. → Paired in-outdoor sampling of PM2.5, PM10-2.5, reflectance [black carbon(BC)], and NO2 for 16 weeks in 2008 at each school. → Two schools (one in each city) were located in high traffic density areas and the other two in areas of low traffic density. Usage of spatially resolved environmental indictors of traffic pollutants in a range of exposure settings. → Substantial intra-urban spatial variability in pollutant concentrations observed between and within the two cities. - Spatial variability in traffic-mediated pollutant concentrations can exist at the intra-urban level and ambient monitoring sites may not accurately represent these concentration gradients.

  18. Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juarez, Chihuahua (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Raysoni, Amit U., E-mail: auraysoni@miners.utep.edu [Environmental Science and Engineering Ph.D. Program, University of Texas, El Paso, TX 79968 (United States); Sarnat, Jeremy A.; Sarnat, Stefanie Ebelt [Department of Environmental Health, Rollins School of Public Health at Emory University, Atlanta, GA 30322 (United States); Garcia, Jose Humberto [Centro de Investigacion y Desarrollo Tecnologico, Tecnologico de Monterrey, Campus Ciudad Juarez, Ciudad Juarez, Chihuahua 32470 (Mexico); Holguin, Fernando [University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Flores Luevano, Silvia [Interdisciplinary Health Science Ph.D. Program, College of Health Sciences, The University of Texas, El Paso, TX 79968 (United States); Li, Wen-Whai [Environmental Science and Engineering Ph.D. Program, University of Texas, El Paso, TX 79968 (United States); Department of Civil Engineering, University of Texas, El Paso, TX 79968 (United States)

    2011-10-15

    Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO{sub 2}) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.-Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO{sub 2} appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children's exposures to these pollutants vary based on the location of their school. - Highlights: > First binational investigation characterizing traffic air pollutants at four schools in El Paso, USA and Cd. Juarez, Mexico. > Paired in-outdoor sampling of PM{sub 2.5}, PM{sub 10-2.5}, reflectance [black carbon(BC)], and NO{sub 2} for 16 weeks in 2008 at each school. > Two schools (one in each city) were located in high traffic density areas and the other two in areas of low traffic density. > Usage of spatially resolved environmental indictors of traffic pollutants in a range of exposure settings. > Substantial intra-urban spatial variability in pollutant concentrations observed between and within the two cities. - Spatial variability in traffic-mediated pollutant concentrations can exist at the intra-urban level and ambient monitoring sites may not accurately represent these concentration gradients.

  19. Determining Deep Basin Structure of the Hueco and southern Mesilla Bolsons, West Texas, Southern New Mexico and Northern Chihuahua Using Nonseismic Geophysical Techniques

    Science.gov (United States)

    Doser, D. I.; Avila, V.; Budhathoki, P.; Marrufo, S.; Montana, C. J.; Kaip, G.; Moncada, M.; Dena Ornelas, O.

    2012-12-01

    The Hueco and southern Mesilla bolsons are the primary groundwater source for much of the El Paso/Ciudad Juarez metropolitan region of over 1 million residents. The bolsons lie at the point where the strike of the southern Rio Grande rift changes from north-south to northwest-southeast, likely due to its interaction with pre-existing Mesozoic and Paleozoic structures. Tectonic activity continues with recent (< 750,000 years) movement along basin bounding and low level (M<4) seismicity. Over the past 4 years we have been using a conjunction of microgravity, magnetic, water well logs and electrical resistivity studies to image the complex structure of these basins within a heavily urbanized environment. These studies suggest the presence of several northwest-southeast striking cross faults within the southern Mesilla Bolson as well as an extensive subsurface andesite body related to the Cristo Rey laccolith. Intrabasin faults in the Hueco Bolson appear to cut the basin into at least 3 smaller subbasins and to control the boundary between fresh and saline water within the aquifer system beneath El Paso. We are also able to trace the East Franklins Mountain fault (last movement < 15,000 ya) at least 15 km south of the U.S.-Mexico border.

  20. Calculation of the structural shielding of the radiotherapy treatment room equipped with a linear accelerator type Tomo therapy Hi-Art in the Oncology Center of Chihuahua, Mexico; Calculo del blindaje estructural de la sala de tratamiento de radioterapia equipada con un acelerador lineal del tipo Tomotherapy Hi-Art en el Centro Oncologico de Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Caballero G, C. A. [Southwest Oncology Centers, North Civic Center Plaza No. 2926, Scottsdale, Arizona (United States); Plascencia, J. C. [Centro Oncologico Louis and Lucille Grado, Republica del Peru No. 102-5, Col. Americas, Aguascalientes (Mexico); Vargas V, M. X.; Toledo J, P., E-mail: cabshm@msn.co [Centro Oncologico de Chihuahua, Hacienda de la Esperanza No. 6304, Fracc. Cima Comercial, Chihuahua (Mexico)

    2010-09-15

    therapy. In this work these specific methodologies are used for the structural shielding calculations of the tomo therapy equipment installed in the Oncology Center of Chihuahua. These calculation methodologies consider the primary radiation, of leakage, disperse, second dispersion and leakage dispersion. The obtained results indicate that due to the lead barrier of the primary beam, the main component that contributes to the shielding requirements of the installation is the leakage radiation. On the other hand, the component that more affects of the door shielding is the dispersion component in the patient. (Author)

  1. Border Environmental Education Resource Guide: Southern New Mexico, South Texas, Northern Chihuahua, Northern Coahuila, Northern Nuevo Leon, Northern Tamaulipas = Guia de Recursos de Educacion Ambiental en la Frontera: Sur de Nuevo Mexico, Sur de Texas, Norte de Chihuahua, Norte de Coahuila, Norte de Nuevo Leon, Norte de Tamaulipas.

    Science.gov (United States)

    Meissner, David, Comp.

    This guide provides educators and residents of the border with useful information about environmental education program offerings along the eastern half of the United States-Mexico border. The programs listed in the guide represent a broad range of educational efforts focused on understanding the environment and solving environmental problems in…

  2. Dust Bowl migration as an analog for possible global warming-induced migration from Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.H.; Longstreth, J.D.; Johnson, A.K.; Rosenberg, N.J.

    1994-06-01

    As a result of increases in CO{sub 2} and other radiatively important trace gases, scientists have predicted increases in mean worldwide temperatures of 2--5 degrees C over the next 50 to 100 years. Such temperature increases may result in climate modifications that would in turn be associated with increases in drought and desertification and could even change the patterns of the monsoons and tropical rains, which are important to agriculture throughout the world. They predicted that the rise in sea level caused by melting and thermal expansion of glaciers and polar icecaps could flood large population centers, destroying habitation and displacing populations. This will result in approximately 50 million ``environmental refugees`` worldwide, triple the number of today. The expected shifts in precipitation are also likely to result in (1) increased runoff contaminated with pesticides, salts, garbage, sewage, and eroded soil, and (2) drought also leading to increased soil erosion and salinization, as well as depletion of limited water resources. The total impact of global warming on agriculture and human habitation could considerably slow the economic development of some nations and would particularly affect agricultural production. Loss of homes, the inability to raise food, an increased prevalence of disease and worsened economic conditions may drive people to leave their homelands, seeking entry into countries which have more resources and greater resistance to the economic consequences of climatic change. This report looks at the possible environmental impacts and economic impacts of the greenhouse effect on Mexico while using the American Dust Bowl event as an analog.

  3. Economía y desarrollo en Chihuahua, México. Una propuesta de análisis regional

    OpenAIRE

    Jorge Arturo Meza Moreno

    2012-01-01

    This essay reviews the links between growth and potential development of a region, in this case focusing on the state of Chihuahua, Mexico. This regional economic study develops a framework that combines growth and competitive dynamics with the potential development model that evaluates de endogenous capacity for development of regions. As a result of the basic findings in this study it is proposed an analytical tool for regional economics named “potential development and territorial situatio...

  4. Jocotitlan, Mexico and Shiveluch, Kamchatka: planetary analog volcanoes for debris avalanche deposits formed by edifice collapse

    Science.gov (United States)

    Sheridan, M. F.; Farley, M.; Siebe, C.

    2001-12-01

    The collapse of volcanic edifices on Earth commonly results in the formation of debris avalanche deposits. Jocotitlán Volcano in Mexico (Siebe et al., 1992) and Shiveluch Volcano in Kamchatka (Belousov et al., 1999) provide remarkably preserved features at several scales that reveal the mechanism of failure and transport of materials. Structures of the remaining edifices on these two volcanoes and characteristics of their deposits are consistent with the model of edifice failure accepted for the 1980 collapse of Mount St. Helens (Voight et al., 1983). Jocotitlán and Shiveluch provide good analogues for deposits of suspected similar origin on Mars, Venus or other planets with large volcanic constructs. Jocotitlan represents a more homogeneous source of layered andesitic lavas whereas the source at Shiveluch was a dacitic dome complex of texturally heterogeneous materials. Both volcanoes have well-preserved summit scarps and display large blocks of materials that slid to a resting place within a few kilometers of the breakaway wall. The volume of collapsed and transported materials in both cases is a few km3 and their deposits from a fan extending for 10-15 km with a H/L value of 0.11. The following features were recognized on the surface of either one or the other of these deposits: numerous flow lobes with different composition and textural characteristics, cross-cutting relationships between flow lobes, steep flow fronts, lateral ridges similar to levees, high bounding ridges at the crater mouth, shadow zones behind large mounds in which vegetation was protected, deep grooves between flow lobes filled with large boulders, tensional gashes sub-normal to flow direction, large blocks consisting of fragile materials that were pushed laterally towards the deposit margin, and decomposition of large coherent surface blocks into conical mounds of fragments. Hummocks are particularly obvious at Jocotitlán Volcano where they are of the size of cinder cones. Where erosion

  5. Vegetation-derived insights on the mobilization and potential transport of radionuclides from the Nopal I natural analog site, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Leslie, B.W.; Pickett, D.A.; Pearcy, E.C.

    1999-07-01

    The Nopal I uranium (U) deposit, Pena Blanca, Mexico is a source term and contaminant transport natural analog to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. In an attempt to characterize the mobilization and potential transport of radionuclides in the unsaturated zone at the Nopal I deposit, vegetation growing on ore piles was analyzed for {sup 238}U, {sup 235}U, and {sup 232}Th decay-series isotopes. Specimens of Phacelia robusta growing on high-grade piles of U ore were collected and analyzed by alpha autoradiography, and by alpha and gamma spectrometry. Activities for U, thorium (Th), and radium (Ra) isotopes (Bq/kg dried plant) were 300, 1,000, and 7,000 for {sup 238}U, {sup 230}Th, and {sup 226}Ra, respectively. The {sup 226}Ra activities in these specimens are among the highest ever measured for plants; furthermore, the plant-to-soil {sup 226}Ra concentration ratio is higher than expected. These results demonstrate the large mobility and bio-availability of Ra in the Nopal I environment, and support previous indications of recent loss of {sup 226}Ra from the ore body. Comparison between the activities of {sup 238}U and {sup 232}Th decay-chain Th isotopes in the plants and in the ore substrate indicate that relative mobilization into pore solutions of {sup 228}Th > {sup 230}Th > {sup 232}Th, in a ratio of about 50--25:4:1, respectively. The similarity of the plant's {sup 234}U/{sup 238}U activity ratio ({approximately}1.2) to that of a caliche deposit that formed adjacent to the Nopal ore body around 54 ka suggests the {sup 234}U/{sup 238}U activity ratio of U released from the ore is approximately 1.2. The U and {sup 226}Ra isotope activities of the plants and ore substrate, and solubility considerations, are used to assess a source term model of the potential Yucca Mountain repository. These results suggest the use of a natural analog source term model in performance assessments may be non-conservative.

  6. Vegetation-derived insights on the mobilization and potential transport of radionuclides from the Nopal I natural analog site, Mexico

    International Nuclear Information System (INIS)

    The Nopal I uranium (U) deposit, Pena Blanca, Mexico is a source term and contaminant transport natural analog to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. In an attempt to characterize the mobilization and potential transport of radionuclides in the unsaturated zone at the Nopal I deposit, vegetation growing on ore piles was analyzed for 238U, 235U, and 232Th decay-series isotopes. Specimens of Phacelia robusta growing on high-grade piles of U ore were collected and analyzed by alpha autoradiography, and by alpha and gamma spectrometry. Activities for U, thorium (Th), and radium (Ra) isotopes (Bq/kg dried plant) were 300, 1,000, and 7,000 for 238U, 230Th, and 226Ra, respectively. The 226Ra activities in these specimens are among the highest ever measured for plants; furthermore, the plant-to-soil 226Ra concentration ratio is higher than expected. These results demonstrate the large mobility and bio-availability of Ra in the Nopal I environment, and support previous indications of recent loss of 226Ra from the ore body. Comparison between the activities of 238U and 232Th decay-chain Th isotopes in the plants and in the ore substrate indicate that relative mobilization into pore solutions of 228Th > 230Th > 232Th, in a ratio of about 50--25:4:1, respectively. The similarity of the plant's 234U/238U activity ratio (∼1.2) to that of a caliche deposit that formed adjacent to the Nopal ore body around 54 ka suggests the 234U/238U activity ratio of U released from the ore is approximately 1.2. The U and 226Ra isotope activities of the plants and ore substrate, and solubility considerations, are used to assess a source term model of the potential Yucca Mountain repository. These results suggest the use of a natural analog source term model in performance assessments may be non-conservative

  7. y Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Socorro Arzaluz Solano

    2006-01-01

    Full Text Available El artículo aborda la aplicación del Programa Hábitat, diseñado por el Gobierno de Vicente Fox en 2002, en dos ciudades fronterizas: Nogales, Sonora, y Ciudad Juárez, Chihuahua. Se analiza la implantación del programa atendiendo sus particularidades, entre otros aspectos, se señalan los diferentes agentes que intervinieron en la ejecución de Hábitat, que pese a la claridad de las reglas, fueron diferentes en cada caso. También, las forma s de participación ciudadana promovidas por los gobiernos locales en ambos casos. Se presentan una reflexión final sobre el desarrollo de Hábitat en la frontera norte, y algunas recomendaciones.

  8. Mexico

    Science.gov (United States)

    2002-01-01

    This true-color image of Mexico was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. In areal extent, Mexico is the third largest country on the continent of North America (not counting Greenland, which is a province of Denmark), comprised of almost 2 million square kilometers (756,000 square miles) of land. Home to roughly 100 million people, Mexico is second only to the United States in population, making it the world's largest Spanish-speaking nation. To the north, Mexico shares its border with the United States-a line that runs some 3,100 kilometers (1,900 miles) east to west. About half of this border is defined by the Rio Grande River, which runs southeast to the Gulf of Mexico (partially obscured by clouds in this image) and marks the dividing line between Texas and Mexico. Toward the upper left (northwest) corner of this image is the Baja California peninsula, which provides the western land boundary for the Gulf of California. Toward the northwestern side of the Mexican mainland, you can see the Sierra Madre Occidental Mountains (brownish pixels) running southeast toward Lake Chapala and the city of Guadalajara. About 400 km (250 miles) east and slightly south of Lake Chapala is the capital, Mexico City. Extending northward from Mexico City is the Sierra Madre Oriental Mountains, the irregular line of brownish pixels that seem to frame the western edges of the bright white cumulus clouds in this image. Between these two large mountain ranges is a large, relatively dry highland region. To the south, Mexico shares borders with Guatemala and Belize, both of which are located south of Mexico's Yucatan Peninsula. Image courtesy Reto Stockli, Brian Montgomery, and Robert Simmon, based on data from the MODIS Science Team

  9. Mexico.

    Science.gov (United States)

    1988-02-01

    Focus in this discussion of Mexico is on the following: geography; the people; history; political conditions; the economy; foreign relations; and relations between the US and Mexico. As of July 1987, the population of Mexico numbered 81.9 million with an estimated annual growth rate of 2.09%. 60% of the population is Indian-Spanish (mestizo), 30% American Indian, 9% white, and 1% other. Mexico is the most populous Spanish-speaking country in the world and the 2nd most populous country in Latin America. Education is decentralized and expanded. Mexico's topography ranges from low desert plains and jungle-like coastal strips to high plateaus and rugged mountains. Hernan Cortes conquered Mexico in 1919-21 and founded a Spanish colony that lasted for almost 300 years. Independence from Spain was proclaimed by Father Miguel Hidalgo on September 16, 1810; the republic was established on December 6, 1822. Mexico's constitution of 1917 provides for a federal republic with a separation of powers into independent executive, legislative, and judicial branches of government. Significant political themes of the administration of President Miguel de la Madrid Hurtado, who began his 6-year term in 1982, have been restructuring the economy, liberalizing trade practices, decentralizing government services, and eliminating corruption among public servants. In 1987, estimates put the real growth of the Mexican economy at 1.5%; the gross domestic product (GDP) had shrunk by 3.5% in 1986. Yet, on the positive side, Mexico's international reserves increased to record levels in 1987 (to about $15 billion), and its current account surplus reached more than $3 billion. Mexico has made considerable progress in moving to restructure its economy. It has substantially reduced impediments to international trade and has moved to reduce the number of parastatal firms. 1987 was the 2nd consecutive year in which Mexico recorded triple-digit inflation; inflation reached 158.8%. Other problems include

  10. Heterogeneous Seepage at the Nopal I Uranium Mine, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The primary objective of this analogue study is to evaluate flow and transport processes of relevance to the proposed Yucca Mountain repository. Seepage data obtained from this study will be used to constrain flow and transport models being developed for the Nopal I system

  11. Mexico.

    Science.gov (United States)

    1984-09-01

    Although Mexico has serious economic and population growth problems, the country is making progress toward solving both of these problems. Mexico has a population of 77.7 million and a population density of 102 persons/square mile. The country has a birth rate of 32/1000, a death rate of 6/1000, and an annual growth rate of 2.6%. The estimated infant mortality rate is 55/1000. The median age of the population is 17.4. Mexico City, with a population of 15 million, is the 3rd largest city in the world, and by 1995, it is expected to be the largest city in the world, with a projected population of 25.2 million. The government vigorously promotes family planning, and the annual population growth rate slowed down from a high of 3.2% in 1970-75 to the current rate of 2.6%. Mexico hopes to achieve replacement level fertility by the year 2000. Other government policies promote income equality, agricultural development, and regional equalization of population growth. In 1982 Mexico's per capita income was US$2270, exports totaled US$21 billion, and imports totaled US$15 billion. By 1976, Mexico's international debt was US$30.2 billion, and inflation was rampant. Recently, the newly elected president, Miguel de la Madrid of the Partido Revolucionario Institutional, obtained a grant of US$39 million from the International Monetary Fund and removed price controls. These efforts should help stabilize Mexico's economy. The country will also need to expand its exports and increase its cultivatable acreage. PMID:12339665

  12. Mexico.

    Science.gov (United States)

    1993-01-01

    The background notes on Mexico provide text and recent statistical information on the geography, population, government, economy, and foreign relations, specifically the North American Free Trade Agreement with US. The 1992 population is estimated at 89 million of which 60% are mestizo (Indian-Spanish), 30% are American Indian, 9% are Caucasian, and 1% are other. 90% are Roman Catholic. There are 8 years of compulsory education. Infant mortality is 30/1000 live births. Life expectancy for males is 68 years and 76 years for females. The labor force is comprised of 30% in services, 24% in agriculture and fishing, 19% in manufacturing, 13% in commerce, 7% in construction, 4% in transportation and communication, and .4% in mining. There are 31 states and a federal district. Gross domestic product (GDP) per capita was $3200 in 1991. Military expenditures were .5% of GDP in 1991. The average inflation rate is 19%. Mexico City with 20 million is the largest urban center in the world. In recent years, the economy has been restructured with market oriented reforms; the result has been a growth of GDP of 3.6% in 1991 from 2% in 1987. Dependence on oil exports has decreased. There has been privatization and deregulation of state-owned companies. Subsidies to inefficient companies have been stopped. Tariff rates were reduced. The financial debt has been reduced and turned into a surplus of .8% in 1992. Mexico's foreign debt has been reduced from its high in 1987 of $107 billion. Agricultural reforms have been ongoing for 50 years. Land was redistributed, but standards of living and productivity have improved only slightly. Rural land tenure regulations have been changed, and other economic reforms are expected. Mexico engages in ad hoc international groups and is selective about membership in international organizations. PMID:12178052

  13. Radiologic inspection in an office built rod contaminated with radioactive material, in Tiaquepaque, Jalisco, Mexico; Inspeccion radiologica en una oficina construida con varilla contaminada con material radiactivo, en Tlaquepaque, Jalisco, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Salas Mar, B.

    2011-07-01

    Note that in 1983 took place {sup T}he most important radiological accident occurred in Mexico in recent years occurred in Ciudad Juarez, Chihuahua, consisting ea involuntary casting a source of Cobalt-60 (originally intended for medical use in teletherapy) and manufacture of rods for the construction and steel bases for tables, in the smelter {sup S}teel de Chihuahua{sup ,} so presumably, that the rods of the office of Tlaquepaque, come from the radiological accident.

  14. {sup 26}Al production: The Allende meteorite (Chihuahua) stellar nucleosynthesis and solar models

    Energy Technology Data Exchange (ETDEWEB)

    Araujo-Escalona, V.; Andrade, E.; Barrón-Palos, L.; Canto, C.; Favela, F.; Huerta, A.; Lucio, O. de; Ortiz, M. E.; Solís, C.; Chávez, E., E-mail: chavez@fisica.unam.mx [Instituto de Física, UNAM (Mexico)

    2015-07-23

    In 1969 a meteorite fell near the small town of Allende, state of Chihuahua in the north of Mexico. Its study yielded information that changed the current understanding of the solar model. In particular traces of {sup 26}Al were found. Abundances of that isotope had been seen in the universe and were related to regions of active heavy nucleosynthesis. Its presence on the solar system was unexpected. It is now understood that cosmic rays induce nuclear reactions on materials to produce {sup 26}Al, on Earth this is well known and it is the basis of many environmental studies, so it is not only the product of some high metalicity star collapse. Taking advantage of the recently reinforced laboratory infrastructure of the Instituto de Física, at UNAM in Mexico City, we proposed to measure the cross section for {sup 26}Al production via some of the most likely reactions, from the nuclear physics point of view (highest Q-values). In this paper the study of the {sup 28}Si(d,α){sup 26} Al nuclear reaction is shown. A target is prepared by a mixture of silicon and aluminum powders. It is irradiated with a deuteron beam (≈1 µA current) at the MV CN-Van de Graaff accelerator laboratory. The number of projectiles is deduced by Rutherford Backscattering Spectrometry (RBS). The produced {sup 26}Al nuclei are then counted at the Accelerator Mass Spectrometry Laboratory.

  15. 26Al production: The Allende meteorite (Chihuahua) stellar nucleosynthesis and solar models

    Science.gov (United States)

    Araujo-Escalona, V.; Andrade, E.; Barrón-Palos, L.; Canto, C.; Favela, F.; Huerta, A.; de Lucio, O.; Ortiz, M. E.; Solís, C.; Chávez, E.

    2015-07-01

    In 1969 a meteorite fell near the small town of Allende, state of Chihuahua in the north of Mexico. Its study yielded information that changed the current understanding of the solar model. In particular traces of 26Al were found. Abundances of that isotope had been seen in the universe and were related to regions of active heavy nucleosynthesis. Its presence on the solar system was unexpected. It is now understood that cosmic rays induce nuclear reactions on materials to produce 26Al, on Earth this is well known and it is the basis of many environmental studies, so it is not only the product of some high metalicity star collapse. Taking advantage of the recently reinforced laboratory infrastructure of the Instituto de Física, at UNAM in Mexico City, we proposed to measure the cross section for 26Al production via some of the most likely reactions, from the nuclear physics point of view (highest Q-values). In this paper the study of the 28Si(d,α)26 Al nuclear reaction is shown. A target is prepared by a mixture of silicon and aluminum powders. It is irradiated with a deuteron beam (≈1 µA current) at the MV CN-Van de Graaff accelerator laboratory. The number of projectiles is deduced by Rutherford Backscattering Spectrometry (RBS). The produced 26Al nuclei are then counted at the Accelerator Mass Spectrometry Laboratory.

  16. Mexico

    International Nuclear Information System (INIS)

    This document summarizes the key energy data for Mexico: 1 - energy organizations and policy: Ministry of energy (SENER), Comision Reguladora de Energia (CRE), Ministry of Finances, Ministry of trade and industrial development (SECOFI), national commission for energy savings (CONAE); 2 - companies: federal commission of electricity (CFE), Minera Carbonifera Rio Escondido (MICARE - coal), Pemex (petroleum); 3 - energy production: resources, electric power, petroleum, natural gas; 4 - energy consumption; 5 - stakes and perspectives. Some economic and energy indicators are summarized in a series of tables: general indicators, supply indicators (reserves, refining and electric capacity, energy production, foreign trade), demand indicators (consumption trends, end use, energy independence, energy efficiency, CO2 emissions), energy status per year and per energy source. (J.S.)

  17. Dose by 222 Rn in houses of the Chihuahua city

    International Nuclear Information System (INIS)

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the 226 Ra that generates to the 222 Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the 222 Rn should not surpass the 148 Bq/m3, since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were selected. The quantification of

  18. The fuel consumption increase in Ciudad Juarez, Chihuahua

    OpenAIRE

    Thomas M Fullerton Jr; Gabriel Muñoz Sapien; Martha Patricia Barraza de Anda; Lisbeily Domínguez Ruvalcaba

    2012-01-01

    This research analyzes short–run gasoline consumption dynamics in Ciudad Juárez, Chihuahua, México. Parameter estimation is carried out using linear transfer function arima analysis. This market is of interest because it is influenced by regional, national, and international economic conditions due to its location on the border with the United States. Explanatory variables that satisfy the significance criterion include the real price of gasoline in Ciudad Juárez, the price of gasoline in Ciu...

  19. Spatial Analysis of the National Evaluation of Scholastic Achievement (ENLACE in Schools of the Municipality of Juarez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Luis Ernesto Cervera Gómez

    2008-05-01

    Full Text Available This research was focused on analyzing the results of the first National Assessment of Academic Achievement for Scholar Centers (ENLACE; acronym in Spanish applied during the year 2006 in the Municipality of Juarez (State of Chihuahua, Mexico. In order to conduct the spatial analysis a geographical information system (GIS was used to make a georeferenced database were all variables were connected to a point representing a school. Results of the examinations expressed as deficient, elemental, good en excellent were spatially distributed over the urban area of Ciudad Juárez. Apparently there is a high spatial correlation between ENLACE’s results with the socioeconomic level of people. In this way results going from good to excellent were spatially located over the sectors more developed of the city. Poor results going from Insufficient to Elemental were spatially located at places with higher deficits of infrastructure and low socioeconomic levels.

  20. Nationwide survey of radon levels in indoor workplaces in Mexico using Nuclear Track Methodology

    International Nuclear Information System (INIS)

    This report presents the preliminary results of an indoor workplace radon survey conducted during 2006-2007. Monitoring was carried out in 24 of the 32 federal entities of Mexico, incorporating 26 cities and 288 locations. The area monitored was divided into 8 regions for the purposes of the study: Chihuahua (a state with uranium mines), North-Central, South-Central, Southeast, South, Northeast, Northwest, and West. These regions differ in terms of geographic and geological characteristics, climate, altitude, and building materials and architectonic styles. Nuclear Track Methodology (NTM) was employed for the survey, using a passive closed-end cup device with Poly Allyl Diglycol Carbonate (PADC), known by its trade name CR-39 (Lantrack), as detector material. Well-established protocols for making continuous indoor radon measurements were followed, including one-step chemical etching in a 6.25 M KOH solution at 60 ± 1 deg. C with an etching time of 18 h. The track densities were determined with an automatic digital system at the Instituto de Fisica de la Universidad Nacional Autonoma de Mexico (IFUNAM) (Physics Institute of the National Autonomous University of Mexico), and calibrated in facilities at the Oak Ridge National Laboratory (ORNL). The importance of this survey lies in the fact that it represents the first time a nationwide survey of radon levels in indoor workplaces has been carried out in Mexico. Mean indoor radon levels from continuous measurements taken during and after working hours ranged from 13 Bq m-3 (the lower limit of detection) to 196 Bq m-3. Analogous official controls or regulations for radon levels in indoor workplaces do not exist in Mexico. The survey described here contributes to knowledge of the natural radiological environment in workplaces, and will aid the relevant authorities in establishing appropriate regulations. The survey was made possible by the efforts of both a private institutions and the Dosimeter Application Project of

  1. Catolicismo social, mutualismo y revolución en Chihuahua

    Directory of Open Access Journals (Sweden)

    Pedro Salmerón Sanginés

    2008-06-01

    Full Text Available El presente artículo muestra una de las fuentes de la Revolución Mexicana más defectuosamente conocidas -el catolicismo social- y su concatenación con el movimiento encabezado por Francisco Villa, sus demandas obreras y políticas y sus modelos de gobierno, mediante la figura de varios dirigentes entre los que destaca Silvestre Terrazas Enríquez. Asimismo destaca el trabajo de organización de las sociedades mutualistas obreras y de la prensa de posición católica, durante el Porfiriato, con la revolución en Chihuahua.This article shows one of the most misunderstood sources of the Mexican Revolution, social catholicism and its link with the movement led by Francisco Villa, its workers' and political demands and models of government, through the figure of various leaders, particularly Silvestre Terrazas Enríquez, and the organizational work of workers' mutual societies and the catholic press during the Porfiriato with the revolution in Chihuahua.

  2. An Ethnographic Study of Special Education Services in a Rural Area of Mexico.

    Science.gov (United States)

    Argus-Calvo, Beverley; And Others

    1996-01-01

    Overviews the current status of special education programs in Mexico in general and in Ciudad Juarez (Chihuahua) and surrounding rural areas. Two special education administrators employed in the Ciudad Juarez school system discuss problems associated with teacher training and lack of administrative support, and the importance of parental and…

  3. Bradyrhizobia from Wild Phaseolus, Desmodium, and Macroptilium Species in Northern Mexico

    OpenAIRE

    Parker, Matthew A.

    2002-01-01

    rRNA genetic markers were analyzed in 97 isolates of nodule bacteria from six legume species in Chihuahua, Mexico. The most common genotypes were widely shared across host species and had 16S rRNA sequences identical to those of strains from an eastern North American legume (Amphicarpaea) that are closely related to Bradyrhizobium elkanii.

  4. The fuel consumption increase in Ciudad Juarez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Thomas M. Fullerton Jr

    2012-07-01

    Full Text Available This research analyzes short–run gasoline consumption dynamics in Ciudad Juárez, Chihuahua, México. Parameter estimation is carried out using linear transfer function arima analysis. This market is of interest because it is influenced by regional, national, and international economic conditions due to its location on the border with the United States. Explanatory variables that satisfy the significance criterion include the real price of gasoline in Ciudad Juárez, the price of gasoline in Ciudad Juárez relative to that charged across the border in el Paso, Texas, USA, and formal sector employment in Ciudad Juárez. Out–of–sample simulations indicate that the model is relatively accurate for forecasts of to 1 to 24 months into the future.

  5. Hidrogeochemistry of Maguarichi's thermal waters, Chihuahua, México

    Science.gov (United States)

    Villalobos-Aragon, A.; Rascon-Oaxaca, E.; Espejel-Garcia, V. V.

    2012-12-01

    The surface expression of the Piedras de Lumbre Geothermal Zone comprises hot springs and steaming fumaroles, which occur in the vicinity of fractures within the rhyolites related to the Sierra Madre Occidental. Waters from hot springs and fumaroles were sampled in order to classify their temperature, hydrogeochemical behavior and origin. Maguarichi, is located in the southwestern part of the mexican state of Chihuahua, in the high Sierra Tarahumara, 350 km southwest from Chihuahua City. Previous work characterized the water as having a sulfate-chloride and sodium-chloride composition, and a temperature (calculated with geothermometers) of 130°C. In 2001, after close to ten years of geological, geochemical and geophysical work made by the Mexican Federal Electrical Commission (CFE), a small geothermal power plant was installed at a cost of US$1.3 million. This small (300 kW) binary-cycle unit supplied energy to the nearby Maguarichi village, 6 kilometers away. The unit was dismantled in 2007 when the electric grid reached the village. In 2012, after a visit by the Mexican president, a plan to develop this area as a touristic attraction is under way. In order to determine the hydrogeochemistry of the thermal waters, two sampling expeditions (October 2011 and May 2012) were performed and the preliminary results show that samples have temperatures ranging from 80°C to 98°C, with major ion and heavy element concentrations below the maximum permissible levels for human consumption waters (NOM-127-SSA1-1994). Sulfate values range from 198 to 222 mg/l, while arsenic ranges from 0.009 to 0.015mg/l. By using H and O stable isotopes we expect to determine the origin of this waters (meteoric or magmatic).

  6. International Uranium Resources Evaluation Project (IUREP) national favourability studies: Mexico

    International Nuclear Information System (INIS)

    Reserves of uranium are located in the north eastern part of Mexico, primarily in the states of Tamaulipas and Chihuahua. Most of the remainder of Mexico's reserves are near the Tamaulipas-Neuvo Leon state border in the Tertiary Frio Formation, where they apparently occur in the types of uranium deposits found in Texas, U.S.A. There are two deposits, La Coma and Buenavista, but nothing has been published on dimensions of the ore bodies. Forty-five miles northeast of Hermosillo, in Sonora state is the Los Amoles district where uranium is found associated with gold and other metals in low-grade deposits on the margins of a Cretaceous batholith. Another occurrence is reported in the mining district of Placer de Guadelupe and Puerto del Aire, about 40-50 km northeast of Chihuahua City, in the state of Chihuahua. Reserves of U3O8 which were published in January 1977 by Nuclear Exchange Corporation of Menlo Park, California, are listed. The government of Mexico has not estimated potential resources. It should be noted that much of Mexico appears favourable for uranium, and only 10 percent has been explored. According to NUEXCO (1977), efforts to find uranium are being increased in an attempt to supply Mexico's nuclear reactor requirements through 1990. Activity is reported to be centered in Tamaulipas and Chihuahua states and to a lesser extent in Nueva Leon, Sonora, Coahuila, and Baja California. Major effort will continue to be placed in Chihuahua state to supply the Penna Bianca mill. Correspondence between favorable geological settings for uranium and the geologic regions of Mexico is reported. Mexico is a country with considerable areas that appear promising for discovery of sandstone, vein, and tuff-related deposits. On the other hand, its potential for Precambrian conglomerate and unconformity-related deposits is limited. Considering these geologic factors, as well as the relatively limited amount of exploration done to date, a guesstimate of speculative potential

  7. Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

    OpenAIRE

    Rentería Villalobos, M.; M.E. Montero Cabrera; M. Reyes Cortés; Herrera Peraza, E.F.; A. Rodríguez Pineda; G. Manjón Collado; García Tenorio, R.; CRESPO T.; M. Valenzuela Hernández

    2007-01-01

    Como parte de un proyecto cient´ıfico sobre actividad alfa en agua subterr´anea de consumo humano en la ciudad de Chihuahua, se ha desarrollado la caracterizaci´on de las rocas fuentes de la radiactividad en el valle de Chihuahua. Se determin´o tambi´en la actividad de muestras de agua subterr´anea y de sedimentos. La actividad de los is´otopos de las series radiactivas en las rocas se obtuvo usando espectroscop´ıa gamma de alta resoluci´on. Algunos valores representativos ...

  8. Dose by {sup 222} Rn in houses of the Chihuahua city; Dosis por {sup 222} Rn en casas-habitacion de la ciudad de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.H.; Talamantes F, C. [ITCH II, Ave. de las Industrias 11101, Chihuahua (Mexico); Villalba, M.L. [UACH, Facultad de Ingenieria, Chihuahua (Mexico); Dobson, P.F. [Laboratorio Nacional Lawrence Berkeley, California (United States); Ortalejo M, B. [UACH, Facultad de Enfermeria y Nutriologia, Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2007-07-01

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the {sup 226} Ra that generates to the {sup 222} Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the {sup 222} Rn should not surpass the 148 Bq/m{sup 3}, since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were

  9. Natural radioactivity in soils of the main cities of the State of Chihuahua; Radiactividad natural en suelos de las principales ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.; Montero C, M.E.; Villalba, L. [CIMAV, Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2003-07-01

    The state of Chihuahua counts with at least 56 uranium zones or of minerals associated to this, being Pena Blanca the greatest and more important deposit of the country. Some of the main cities of the state are near to these deposits, as Aldama and Chihuahua. Its were took samples of soil of 11 cities of the state to determine the natural activity of radionuclides. It was determined the specific activity attributable to the parents of the series of {sup 238} U, {sup 232} Th, and of the {sup 40} K isotopes, as well as effective dose rate H{sub E} in the soil samples. It was used the high resolution gamma spectrometry of a high purity Ge detector in the laboratory of Environmental Radiological Surveillance of the CIMAV. The measure of the activity of the uranium series carries out by means of the lines of 351 KeV of the {sup 214} Pb and of 609 keV of the {sup 214} Bi, while the thorium series it was deduced of the lines of 238 keV of the {sup 212} Pb and of 912 keV of the {sup 228} Ac. Its were carried out copies and replies for the quality control. Its were found high values of specific activity of some radionuclides, in the near cities to uranium deposits like Aldama and Chihuahua. For the cities that are not near to deposits, as Ciudad Juarez and Ojinaga, the found values were normal. Also the effective dose rate was high for the near cities to deposits like Aldama, Bocoyna, Chihuahua, Jimenez and Nuevo Casas Grandes, it is also necessary to determine, the radon in air levels and of radionuclides in consumption water to obtain the dose that the population of those populations receives. (Author)

  10. Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

    International Nuclear Information System (INIS)

    As part of a scientific research project about alpha radioactivity in groundwater for human consumption at the Chihuahua City, the characterization of rock sources of radioactivity around de Chihuahua valley was developed. The radioactivity of groundwater and sediments was determined, too. The radioactivity of uranium- and thorium- series isotopes contained in rocks was obtained by high resolution gamma-ray spectroscopy. Some representative values are 50 Bq/kg for the mean value of Bi-214 activity, and 121.5 Bq/kg for the highest value at West of the city. The activity of sediments, extracted during wells perforation, was determined using a Nal(TI) detector. A non-reported before uranium ore was localized at the San Marcos range formation. Its outcrops are inside the Chihuahua-Sacramento valley basin and its activity characterization was performed. Unusually high specific uranium activities, determined by alpha spectrometry, were obtained in water, plants, sediments and fish extracted at locations close to outcrops of uranium minerals. The activity of water of the San Marcos dam reached 7.7 Bq/L. The activity of fish, trapped at San Marcos dam, is 0.99 Bq/kg. Conclusions about the contamination of groundwater at North of Chihuahua City were obtained. (Author)

  11. Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

    Energy Technology Data Exchange (ETDEWEB)

    Renteria V, M.; Montero C, M.E.; Reyes C, M.; Herrera P, E.F.; Valenzuela H, M. [Centro de lnvestigacion en Materiales Avanzados, Miguel de Cervantes 120, 31109 Chihuahua, (Mexico); Rodriguez P, A. [World Wildlife Fund (WWF), Chihuahuan Desert Program, Coronado 1005, 31000 Chihuahua (Mexico); Manjon C, G.; Garcia T, R. [Universidad de Sevilla, Departamento de Fisica Aplicada 11, ETS Arquitectura, Av. Reina Mercedes 2, 41012 Sevilla, (Spain); Crespo, T. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Av. Complutense 22, 28040 Madrid, (Spain)]. e-mail: elena.montero@cimav.edu.mx

    2007-07-01

    As part of a scientific research project about alpha radioactivity in groundwater for human consumption at the Chihuahua City, the characterization of rock sources of radioactivity around de Chihuahua valley was developed. The radioactivity of groundwater and sediments was determined, too. The radioactivity of uranium- and thorium- series isotopes contained in rocks was obtained by high resolution gamma-ray spectroscopy. Some representative values are 50 Bq/kg for the mean value of Bi-214 activity, and 121.5 Bq/kg for the highest value at West of the city. The activity of sediments, extracted during wells perforation, was determined using a Nal(TI) detector. A non-reported before uranium ore was localized at the San Marcos range formation. Its outcrops are inside the Chihuahua-Sacramento valley basin and its activity characterization was performed. Unusually high specific uranium activities, determined by alpha spectrometry, were obtained in water, plants, sediments and fish extracted at locations close to outcrops of uranium minerals. The activity of water of the San Marcos dam reached 7.7 Bq/L. The activity of fish, trapped at San Marcos dam, is 0.99 Bq/kg. Conclusions about the contamination of groundwater at North of Chihuahua City were obtained. (Author)

  12. Interferon Analogs

    NARCIS (Netherlands)

    Poelstra, Klaas; Prakash, Jai; Beljaars, Eleonora; Bansal, Ruchi

    2015-01-01

    The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least

  13. Interferon Analogs

    NARCIS (Netherlands)

    Poelstra, Klaas; Prakash, Jai; Beljaars, Leonie; Bansal, Ruchi

    2010-01-01

    The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least

  14. Country nuclear fuel cycle profile: Mexico

    International Nuclear Information System (INIS)

    The two BWRs at the Laguna Verde facility, which have a combined capacity of 1308 MW(e), generated 5% of domestic electricity production (9.6 TW.h) in 2002. mexico has not yet decided about its nuclear fuel cycle policy. The Mining Development Commission operated a plant at Villa Aldama, Chihuahua from 1969 to 1971. The facility recovered molybdenum and byproduct uranium from ores mined in the Sierra de Gomez, Domitilia and other localities. A total of 49 t U was produced. At present, there are no plans to resume uranium production. Uranium enrichment is not undertaken domestically, requirements being met by USEC Inc., USA. Fuel fabrication requirements are met by GNF, USA. A fuel fabrication facility (capacity 5 t HM/a) of the Centro Nuclear de Mexico BWR was in operation from 1980 to 1996 when it was shut down for economic reasons. Spent fuel is stored at the reactor site

  15. Factors Influencing Neotropical River Otter Habitat Use in Central Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Carillo-Rubio

    2004-01-01

    Full Text Available Research regarding the habitat use of the neotropical river otter (Lontra longicaudis is lacking. I assessed habitat use by the species in the San Pedro River of northern México using presence/absence (i.e., detection/non‐detection data from 21 used and 25 randomly‐selected unused sites. The best fitting logistic regression models and principal component ordination reveal that river otters prefer habitat patches dominated by large, deep pools with nearby talus/rock cover and densely vegetated riverbanks. I mention the importance of understanding habitat use patterns for river otter ecology and conservation and the usefulness of presence/absence data in population ecology and conservation planning research.

  16. REGIONAL HYDROLOGY OF THE NOPAL 1 SITE, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Rodriguez-Pineda; P. Goodell; P. Dobson; J. Walton; R. Olver; R. de la Garza; S. Harder

    2005-10-01

    The objectives of this report are: (1) Determine the main source of the groundwater (GW) found within the DOE wells (PB-1, PB-2, and PB-3); and (2) Determine whether the Nopal I GW has any relationship to the connectivity between the regional Encinillas Aquifer to the west and the El Cuervo Aquifer to the east.

  17. INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    Three test wells, PB-1, PB-2, and PB-3, were drilled at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes during March-April 2003. The initial pumping to condition the wells was completed during December 2003. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was continuously cored to a depth of 250 m, terminating 20 m below the top of the measured water level. The PB-2 and PB-3 wells, which were drilled on opposite sides of PB-1 at a radial distance of approximately 40 to 50 m outside of the remaining projected ore body, were also drilled to about 20 m below the top of the measured water level. Each test well was completed with 4-inch (10.2-cm) diameter PVC casing with a slotted liner below the water table. Initial conditioning of all three wells using a submersible pump at low pump rates [less than 1 gallon (3.8 1) per minute] resulted in measurable draw down and recoveries. The greatest drawdown (∼15 m) was observed in PB-2, whereas only minor (<1 m) drawdown occurred in PB-3. For PB-1 and PB-2, the water turbidity decreased as the wells were pumped and the pH values decreased, indicating that the contamination from the drilling fluid was reduced as the wells were conditioned. Test wells PB-1 and PB-2 showed increased inflow after several borehole volumes of fluid were removed, but their inflow rates remained less that the pumping rate. Test well PB-3 showed the smallest drawdown and least change in pH and conductivity during initial pumping and quickest recovery with a rise in measured water level after conditioning. The 195 gallons (750 l) of water pumped from PB-3 during conditioning was discharged through a household sponge. That sponge showed measurable gamma radiation, which decayed to background values in less than 12 hours. Preliminary interpretations include filtration of a radioisotope source with a short half-life or of a radioisotope that volatized as the sponge dried, such as Rn-222 and its short-lived daughters. No filtration was used during the pumping of PB-1 or PB-2

  18. STRATIGRAPHY OF THE PB-1 WELL, NOPAL 1 URANIUM DEPOSIT, PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    P. Dobson

    2005-09-14

    The objectives of this report are: (1) Stratigraphic study part of integrated research project examining migration of radionuclides at Pena Blanca; (2) Immediate objectives of study include: locate stratigraphic contacts in third dimension; measure rock properties (matrix permeability, porosity, mineralogy, cation exchange capacity) of cored section; determine fracture frequency and orientation; (3) Results of study serve as primary inputs to flow and transport models.

  19. Stratigraphy of the PB-1 well, Nopal I uranium deposit, Sierra Pena Blanca, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The Nopal I site in the Pena Blanca uranium district has a number of geologic and hydrologic similarities to the proposed high-level radioactive waste repository at Yucca Mountain, making it a useful analogue to evaluate process models for radionuclide transport. The PB-1 well was drilled in 2003 at the Nopal I uranium deposit as part of a DOE-sponsored natural analogue study to constrain processes affecting radionuclide transport. The well penetrates through the Tertiary volcanic section down to Cretaceous limestone and intersects the regional aquifer system. The well, drilled along the margin of the Nopal I ore body, was continuously cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. Detailed observations of these units were afforded through petrographic description and rock-property measurements of the core, together with geophysical logs of the well. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich, rhyolitic ash-flow tuff. This cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, goethite, jarosite, and opal. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the Nopal Formation is the Coloradas Formation, which consists of a welded lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation consists of poorly sorted conglomerate containing clasts of subangular to subrounded fragments of volcanic rocks, limestone, and chert. Three thin (2-6 m) intervals of intercalated pumiceous tuffs were observed within this unit. The contact between the Pozos Formation and the underlying Cretaceous limestone basement was observed at a depth of 244.40 m. The water table is located at a depth of ∼223 m. Several zones with elevated radioactivity in the PB-1 core are located above the current water table. These zones may be associated with changes in redox conditions that could have resulted in the precipitation of uraninite from downward flowing waters transporting U from the overlying Nopal deposit. All of the intersected units have low (typically submillidarcy) matrix permeability, thus fluid flow in this area is dominated by fracture flow. These stratigraphic and rock-property observations can be used to constrain flow and transport models for the Pena Blanca natural analogue

  20. STRATIGRAPHY OF THE PB-1 WELL, NOPAL 1 URANIUM DEPOSIT, PENA BLANCA, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    The objectives of this report are: (1) Stratigraphic study part of integrated research project examining migration of radionuclides at Pena Blanca; (2) Immediate objectives of study include: locate stratigraphic contacts in third dimension; measure rock properties (matrix permeability, porosity, mineralogy, cation exchange capacity) of cored section; determine fracture frequency and orientation; (3) Results of study serve as primary inputs to flow and transport models

  1. STRATIGRAPHY OF THE PB-1 WELL, NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2005-06-25

    Three wells, PB-1, PB-2, and PB-3, were drilled in 2003 at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes. The wells penetrate through the Tertiary volcanic section down to the Cretaceous limestone basement, and intersect the top of the regional aquifer system. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich rhyolitic ash-flow tuff. The cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, and goethite. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the basal vitrophyre is the Coloradas Formation, which consists of a welded, lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. The Nopal I ore body is restricted to a brecciated zone that intersects these two volcanic units. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation in the PB-1 core consists of interbedded, poorly sorted sandstone and conglomerate layers. The conglomeratic clasts consist of subangular to subrounded fragments of volcanic rocks, limestone, and chert. Thin (2-6 m) intervals of intercalated pumiceous tuffs were observed within this unit. The contact between the Pozos Formation and the underlying Cretaceous limestone basement was observed at a depth of 244.4 m.

  2. INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    R.D. Oliver; J.C. Dinsmoor; S.J. Goldstein; I. Reyes; R. De La Garza

    2005-07-11

    Three test wells, PB-1, PB-2, and PB-3, were drilled at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes during March-April 2003. The initial pumping to condition the wells was completed during December 2003. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was continuously cored to a depth of 250 m, terminating 20 m below the top of the measured water level. The PB-2 and PB-3 wells, which were drilled on opposite sides of PB-1 at a radial distance of approximately 40 to 50 m outside of the remaining projected ore body, were also drilled to about 20 m below the top of the measured water level. Each test well was completed with 4-inch (10.2-cm) diameter PVC casing with a slotted liner below the water table. Initial conditioning of all three wells using a submersible pump at low pump rates [less than 1 gallon (3.8 1) per minute] resulted in measurable draw down and recoveries. The greatest drawdown ({approx}15 m) was observed in PB-2, whereas only minor (<1 m) drawdown occurred in PB-3. For PB-1 and PB-2, the water turbidity decreased as the wells were pumped and the pH values decreased, indicating that the contamination from the drilling fluid was reduced as the wells were conditioned. Test wells PB-1 and PB-2 showed increased inflow after several borehole volumes of fluid were removed, but their inflow rates remained less that the pumping rate. Test well PB-3 showed the smallest drawdown and least change in pH and conductivity during initial pumping and quickest recovery with a rise in measured water level after conditioning. The 195 gallons (750 l) of water pumped from PB-3 during conditioning was discharged through a household sponge. That sponge showed measurable gamma radiation, which decayed to background values in less than 12 hours. Preliminary interpretations include filtration of a radioisotope source with a short half-life or of a radioisotope that volatized as the sponge dried, such as Rn-222 and its short-lived daughters. No filtration was used during the pumping of PB-1 or PB-2.

  3. STRATIGRAPHY OF THE PB-1 WELL, NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    Three wells, PB-1, PB-2, and PB-3, were drilled in 2003 at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes. The wells penetrate through the Tertiary volcanic section down to the Cretaceous limestone basement, and intersect the top of the regional aquifer system. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich rhyolitic ash-flow tuff. The cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, and goethite. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the basal vitrophyre is the Coloradas Formation, which consists of a welded, lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. The Nopal I ore body is restricted to a brecciated zone that intersects these two volcanic units. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation in the PB-1 core consists of interbedded, poorly sorted sandstone and conglomerate layers. The conglomeratic clasts consist of subangular to subrounded fragments of volcanic rocks, limestone, and chert. Thin (2-6 m) intervals of intercalated pumiceous tuffs were observed within this unit. The contact between the Pozos Formation and the underlying Cretaceous limestone basement was observed at a depth of 244.4 m

  4. Distribution and Fractionation of Uranium Isotopes in Water from San Marcos Dam, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The aim of this work was to assess the fractionation and distribution of isotopic uranium contained in both, suspended matter and water. Uranium was measured in three points along the San Marcos dam: water input, midpoint, and near to dam wall. Every water sample was separated in suspended particulate matter fraction and in dissolved fraction. Likewise, suspended particulate matter was divided and analyzed in three particle size fractions: coarse, medium, and fine. The results show that most uranium was in the suspended particulate matter. The distribution coefficient kd ranged between 1.6 ·101 to 1·103 L/g. In dissolved fraction, high concentrations of 234U were found, where the activity ratio (AR, 238U/234U) ranged from 2.1 to 3.5. In average, uranium contents tend to be concentrated in coarse fraction, with AR near to unit. Medium and fine fractions showed 238U concentration higher than 234U. The highest uranium concentration was at water input point. The highest 238U concentrations were found: in the coarse fraction at the input point, in the medium fraction at the midpoint of the dam, and in the fine fraction by the nearest point of the dam wall. (author)

  5. Volcanic stratigraphy and U-Mo mineralization of the Sierra de Pena Blanca district, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    The Sierra de Pena Blanca district encloses three economic deposits: El Nopal 1, Margaritas and Puerto 3; U-Mo mineralization is confined in the Tertiary volcanic sequence. Locally, this volcanic sequence rests on the Pozos conglomerate, which has predominant calcareous pebbles. Where the Pozos conglomerate was not deposited, the volcanic sequence rests on Albian-Cenomanian limestones. The recently updated Tertiary volcanic stratigraphy consists of a sequence of rhyolitic ash-flow tuffs divided into six simple cooling units interbedded with epiclastic conglomerates. Economic mineralization of El Nopal 1, Margaritas and Puerto 3 is confined to the Tertiary volcanic sequence, mainly in ash-flow tuff sheets of the Escuadra and Nopal Formations, and shows predominant stratigraphic control. The updated stratigraphic and structural characteristics of the deposits, the epithermal essence of mineralization and the lack of any identified intrusive rocks related to the ore fluid generation suggest that the source of this mineralization was not magmatic-hydrothermal. It is more likely to be derived from the diagenetic alteration and leaching of the volcanic glass by a geothermal convective groundwater system

  6. Stratigraphy of the PB-1 well, Nopal I uranium deposit, Sierra Pena Blanca, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, P.; Fayek, M.; Goodell, P.; Ghezzehei, T.; Melchor, F.; Murrell, M.; Oliver, R.; Reyes-Cortes, I.A.; de la Garza, R.; Simmons, A.

    2008-08-01

    The Nopal I site in the Pena Blanca uranium district has a number of geologic and hydrologic similarities to the proposed high-level radioactive waste repository at Yucca Mountain, making it a useful analogue to evaluate process models for radionuclide transport. The PB-1 well was drilled in 2003 at the Nopal I uranium deposit as part of a DOE-sponsored natural analogue study to constrain processes affecting radionuclide transport. The well penetrates through the Tertiary volcanic section down to Cretaceous limestone and intersects the regional aquifer system. The well, drilled along the margin of the Nopal I ore body, was continuously cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. Detailed observations of these units were afforded through petrographic description and rock-property measurements of the core, together with geophysical logs of the well. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich, rhyolitic ash-flow tuff. This cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, goethite, jarosite, and opal. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the Nopal Formation is the Coloradas Formation, which consists of a welded lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation consists of poorly sorted conglomerate containing clasts of subangular to subrounded fragments of volcanic rocks, limestone, and chert. Three thin (2-6 m) intervals of intercalated pumiceous tuffs were observed within this unit. The contact between the Pozos Formation and the underlying Cretaceous limestone basement was observed at a depth of 244.40 m. The water table is located at a depth of {approx}223 m. Several zones with elevated radioactivity in the PB-1 core are located above the current water table. These zones may be associated with changes in redox conditions that could have resulted in the precipitation of uraninite from downward flowing waters transporting U from the overlying Nopal deposit. All of the intersected units have low (typically submillidarcy) matrix permeability, thus fluid flow in this area is dominated by fracture flow. These stratigraphic and rock-property observations can be used to constrain flow and transport models for the Pena Blanca natural analogue.

  7. Factors Influencing Neotropical River Otter Habitat Use in Central Chihuahua, Mexico

    OpenAIRE

    Eduardo Carillo-Rubio

    2004-01-01

    Research regarding the habitat use of the neotropical river otter (Lontra longicaudis) is lacking. I assessed habitat use by the species in the San Pedro River of northern México using presence/absence (i.e., detection/non‐detection) data from 21 used and 25 randomly‐selected unused sites. The best fitting logistic regression models and principal component ordination reveal that river otters prefer habitat patches dominated by large, deep pools with nearby talus/rock cover and densely vegetat...

  8. Chihuahua. Guerra contra el narcotráfico y calentamiento social

    OpenAIRE

    Quintana S., Víctor M.

    2013-01-01

    Chihuahua : Guerre contre le narcotrafic et embrasement social. L’auteur analyse dans cet article la situation de l’État mexicain le plus affecté par la violence au cours des dernières années : le Chihuahua, situé dans le nord du pays près de la frontière avec les États-Unis. Après avoir énuméré les principales manifestations de la violence criminelle et de la violence d’État entre 2007 et 2011 (homicides – notamment de femmes et de jeunes –, disparitions), il analyse ensuite leurs effets (co...

  9. Natural radioactivity in soils of the main cities of the State of Chihuahua

    International Nuclear Information System (INIS)

    The state of Chihuahua counts with at least 56 uranium zones or of minerals associated to this, being Pena Blanca the greatest and more important deposit of the country. Some of the main cities of the state are near to these deposits, as Aldama and Chihuahua. Its were took samples of soil of 11 cities of the state to determine the natural activity of radionuclides. It was determined the specific activity attributable to the parents of the series of 238 U, 232 Th, and of the 40 K isotopes, as well as effective dose rate HE in the soil samples. It was used the high resolution gamma spectrometry of a high purity Ge detector in the laboratory of Environmental Radiological Surveillance of the CIMAV. The measure of the activity of the uranium series carries out by means of the lines of 351 KeV of the 214 Pb and of 609 keV of the 214 Bi, while the thorium series it was deduced of the lines of 238 keV of the 212 Pb and of 912 keV of the 228 Ac. Its were carried out copies and replies for the quality control. Its were found high values of specific activity of some radionuclides, in the near cities to uranium deposits like Aldama and Chihuahua. For the cities that are not near to deposits, as Ciudad Juarez and Ojinaga, the found values were normal. Also the effective dose rate was high for the near cities to deposits like Aldama, Bocoyna, Chihuahua, Jimenez and Nuevo Casas Grandes, it is also necessary to determine, the radon in air levels and of radionuclides in consumption water to obtain the dose that the population of those populations receives. (Author)

  10. Dinámica del Consumo de Gasolina en Ciudad Juárez, Chihuahua

    OpenAIRE

    Fullerton, Thomas M., Jr.; Munoz Sapien, Gabriel; Barraza de Anda, Martha P.; Dominguez Ruvalcaba, Lisbeily

    2011-01-01

    This research analyzes short-run gasoline consumption dynamics in Ciudad Juárez, Chihuahua, México. Parameter estimation is carried out using linear transfer function ARIMA analysis. This market is of interest because it is influenced by regional, national, and international economic conditions due to its location on the border with the United States. Explanatory variables that satisfy the significance criterion include the real price of gasoline in Ciudad Juárez, the price of gasoline in ...

  11. Dinámica del Consumo de Gasolina en Ciudad Juárez, Chihuahua

    OpenAIRE

    Fullerton, Thomas M., Jr.; Munoz Sapien, Gabriel; Barraza de Anda, Martha P.; Dominguez Ruvalcaba, Lisbeily

    2011-01-01

    This research analyzes short-run gasoline consumption dynamics in Ciudad Juárez, Chihuahua, México. Parameter estimation is carried out using linear transfer function ARIMA analysis. This market is of interest because it is influenced by regional, national, and international economic conditions due to its location on the border with the United States. Explanatory variables that satisfy the significance criterion include the real price of gasoline in Ciudad Juárez, the price of gasoline in Ciu...

  12. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  13. Study of the total uranium in underground water in the city of Jimenez, Chihuahua; Estudio del uranio total en agua subterranea en la Ciudad de Jimenez, Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Renteria V, M. [Centro de Investigacion de Materiales Avanzados (CIMAV), Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: marusia.renteria@cimav.edu.mx

    2004-07-01

    Samples of water of wells in the city of Jimenez, Chihuahua were analyzed, and its were determined the content of total uranium. It was used the technique of extraction of uranium from water adding Bis ( 2- ethylexyl) phosphate and scintillating Beta plate Hi safe, and the measures of the activities were carried out in the portable scintillation detector Thiathler- O Y HIDEX. The obtained interval of concentrations was 0.12 to 0.26 Bq/l that it is finds below the maximum permissible limits that it manages the Mexican regulation. It was found a significant correlation among the concentration of uranium and those total solid dissolved present in the samples. (Author)

  14. Las posibilidades de industrialización sustentable de la candelilla en el desierto de Chihuahua

    OpenAIRE

    Hernández García, Guillermo

    2013-01-01

    El objetivo de la investigación que condujo a la elaboración de esta tesis, es el de determinar las posibilidades de industrialización sustentable de la cera de candelilla producida en el desierto de Chihuahua. Para ello, fue necesario estudiar la estructura socio-económica, la cosmovisión y el proceso de trabajo de las comunidades productoras, así como las condiciones de venta del producto. El proceso de investigación comenzó con la delimitación del objeto de estudio y continu...

  15. Del neocorporativismo a nivel fabril maquiladoras y sindicatos en la ciudad de chihuahua, México

    OpenAIRE

    Sergio Sánchez; Patricia Ravelo

    2000-01-01

    En este ensayo buscamos responder una pregunta: ¿Existe en las maquiladoras de exportación de la ciudad de Chihuahua, en el norte industrializado de México, una nueva relación entre el trabajo y el capital, un vínculo neocorporativo? Para dilucidar esta cuestión abordamos varias dimensiones de tal relación entre trabajo y capital: organización del trabajo y empleo; proceso de trabajo; salario; prestaciones sindicales y regresión de derechos. Es una visión pesimista sobre estas relaciones en l...

  16. Los hogares con jefatura femenina y la calidad de vida. Chihuahua y Tijuana, 2005

    OpenAIRE

    Ana María Navarro Ornelas; Raúl Sergio González Ramírez

    2010-01-01

    El objetivo de este trabajo es analizar la calidad de vida de los hogares ubicados en las ciudades de Chihuahua y Tijuana de acuerdo con el sexo del jefe del hogar, para lo cual se construye un índice. Se presenta un panorama sociodemográfico de tales ciudades tomando como base los resultados del ii Conteo de Población y Vivienda 2005; asimismo se formula un análisis de la calidad de vida en los hogares con los datos que ofrece la Encuesta sobre Calidad de Vida, Competitividad y Violencia Soc...

  17. Estimation of Seasonal Risk Caused by the Intake of Lead, Mercury and Cadmium through Freshwater Fish Consumption from Urban Water Reservoirs in Arid Areas of Northern Mexico

    OpenAIRE

    Myrna Nevárez; Leal, Luz O.; Myriam Moreno

    2015-01-01

    Bioavailability and hence bioaccumulation of heavy metals in fish species depends on seasonal conditions causing different risks levels to human health during the lifetime. Mercury, cadmium and lead contents in fish from Chihuahua (Mexico) water reservoirs have been investigated to assess contamination levels and safety for consumers. Muscle samples of fish were collected across the seasons. Lead and cadmium were analyzed by inductively coupled plasma-optical emission spectrometry, and mercur...

  18. Radiation accident of 60Co contamination. Mexico 1984

    International Nuclear Information System (INIS)

    The action taken to mitigate the consequences of a radiation accident occuring in the State of Chihuahua, Mexico, is described, when a no longer in use cobalt-60 teletherapy unit, with radioactive pellets still inside, was sold, unwittingly as ordinary scrap to be finally made into reinforced steel rods. The finished metallic items, unknowingly contaminated with cobalt-60, were subsequently sold in central and northern Mexico and in the United States of America. The junkyard, transport vehicle, several foundries and some streets of two cities and the road between them were also made radioactive by the accident. The discovery of and search for the radioactive metallic products is described as is their final disposal and the decontamination of the affected sites. Individual and collective radiation doses is estimated. (author)

  19. Analog model

    International Nuclear Information System (INIS)

    The invention relates to devices for modelling the space-dependent kinetics of a nuclear reactor. It can be advantageously used in studying the dynamics of the neutron field in the core to determine the effect of the control rods on the power distribution in the core, for training purposes. The proposed analog model of a nuclear reactor comprises operational amplifiers and a grid of resistors simulating neutron diffusion. Connected to the grid nodes are supply resistors modelling absorption and multiplication of neutrons. This is achieved by that, in the proposed model, all resistors through which power is supplied to the grid nodes are interconnected by their other leads and coupled to the output of the amplifier unit common for all nodes. Therewith, the amlifier unit models the transfer function of a ''point'' reactor. Connected to the input of this unit which includes two to four amplifiers are resistors for addition of signals with a grid node. Coupled to the grid nodes via additional resistors are voltage sources simulating reactivity

  20. Relación entre consultas a urgencias por enfermedad respiratoria y contaminación atmosférica en Ciudad Juárez, Chihuahua Relationship between emergency room visits for respiratory disease and atmospheric pollution in Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Leticia Hernández-Cadena

    2000-08-01

    Full Text Available OBJETIVO: Analizar la relación entre las concentraciones ambientales de partículas de diámetro OBJECTIVE: To assess the relationship of <=10 µm particles (PM10 and atmospheric ozone concentrations, with the daily number of emergency visits due to asthma and acute respiratory diseases, among children aged under 15, living in Ciudad Juarez, Chihuahua, Mexico. MATERIAL AND METHODS: Between 1998 and 1999, an ecologic study was conducted. Atmospheric data were obtained from the Environmental Protection Agency (EPA, from eight monitoring stations located in Ciudad Juarez, Chihuahua, and El Paso, Texas. From July 1997 to December 1998, data from emergency room visits for respiratory illness were abstracted from existing medical records of two Mexican Institute of Social Security (IMSS hospitals in Ciudad Juarez. Diagnoses were classified into two groups: a asthma, and b upper respiratory infections (URI, according to the International Classification of Diseases (ICD-9 and/or IDC-10. Statistical analysis was carried out using the Poisson regression time series method. RESULTS: During the study period, the mean 24-hour PM10 level was 34.46 µg/m³ (SD=17.99 and the mean ozone level was 51.60 ppb (SD=20.70. The model shows that an increase of 20 µg/m³ in the mean 24-hour exposure to PM10 was related to an increase of 4.97% (95% CI 0.97-9.13 in emergency visits for asthma, with a 5-day lag, as well as to an increase of 9% (95% CI 1.8-16.8 when a cumulative 5-day exposure was considered. URI increased 2.95% as a cause of emergency room visits, for each 20 µg/m³ increase in the mean 24-hour exposure to PM10. The impact of PM10 on emergency visits for asthma was greater on days with ozone ambient levels exceeded 49 ppb (median value. CONCLUSIONS: A positive association was found between environmental PM10 and ozone concentrations and the daily number of emergency room visits due to asthma and acute respiratory diseases, even with levels lower than the

  1. Investigation of the radioactivity in air, water and soil in the Estado de Chihuahua; Investigacion de la radiactividad en aire, agua y suelo en el Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Montero C, M.E.; Renteria V, M.; Herrera P, E.F.; Villalba, M.L. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109, Chihuahua (Mexico); Colmenero S, L.H. [CIMAV e Instituto Tecnologico de Chihuahua, Av. de las Industrias 11101, Chihuahua (Mexico)]. e-mail: elena.montero@cimav.edu.mx

    2004-07-01

    The results of the determinations of activities of the series of U-238, Th-232 and the K-40 in soils, of the Rn-222 in the air of the domiciles, and in underground water are presented, as well as the total uranium activity in underground water, product of an extensive sampling in the state of Chihuahua. In two of the aquifers a positive correlation was obtained among the concentration of total uranium and the Rn-222 dissolved in the water of each well. Also it was finds a positive tendency among the averages of the concentration of U-238 in the soil and of the concentration of Rn-222 in the air of the domiciles in different towns, and among the averages of the concentration of U-238 in the floor and of the concentration of the Rn-222 dissolved in the well water in different aquifer. It is suggested that the constitution for rocks more or less uraniferous of the alluvial valleys gives explanation to the observed correlations. (Author)

  2. Study of the total uranium in underground water in the city of Jimenez, Chihuahua

    International Nuclear Information System (INIS)

    Samples of water of wells in the city of Jimenez, Chihuahua were analyzed, and its were determined the content of total uranium. It was used the technique of extraction of uranium from water adding Bis ( 2- ethylexyl) phosphate and scintillating Beta plate Hi safe, and the measures of the activities were carried out in the portable scintillation detector Thiathler- O Y HIDEX. The obtained interval of concentrations was 0.12 to 0.26 Bq/l that it is finds below the maximum permissible limits that it manages the Mexican regulation. It was found a significant correlation among the concentration of uranium and those total solid dissolved present in the samples. (Author)

  3. Del neocorporativismo a nivel fabril maquiladoras y sindicatos en la ciudad de chihuahua, México

    Directory of Open Access Journals (Sweden)

    Sergio Sánchez

    2000-04-01

    Full Text Available En este ensayo buscamos responder una pregunta: ¿Existe en las maquiladoras de exportación de la ciudad de Chihuahua, en el norte industrializado de México, una nueva relación entre el trabajo y el capital, un vínculo neocorporativo? Para dilucidar esta cuestión abordamos varias dimensiones de tal relación entre trabajo y capital: organización del trabajo y empleo; proceso de trabajo; salario; prestaciones sindicales y regresión de derechos. Es una visión pesimista sobre estas relaciones en los “nuevos” contextos de industrialización, pero que, con todo, alcanza a ver un futuro más promisorio para el trabajo.

  4. Advance of the Monitor of Drought for the Northern Region of Mexico

    Science.gov (United States)

    Reyes Gomez, V. M.; Nunez Lopez, D.

    2007-05-01

    In the last 13 years, the State of Chihuahua suffered a lingering drought that caused social, economical and environmental impacts hardly quantifiable. Since 2002, a monitoring system was implemented to watch the evolution of the meteorological drought in Chihuahua, recently being broadened for the states in the North of Mexico. Evaluation of the Meteorological Drought The Monitoring System on the Drought in Chihuahua includes the following steps: missing data gaps were completed basing on the statistical procedures described by Young (1992); the source code, was compiled to create a computer program, with which it can be derived a level of climatic station, historical series of values for the SPI in time scales of 1 to 48 months; under this classification scheme, it is considered that a drought event begins when the values of the SPI are inferior to -0.7 (McKee et al. 1995). The spatial distribution of the SPI was determined through spatial interpolation techniques using a reverse method of the distance between stations included in Arc/Info©. This same procedure was applied for the States of Sonora, Sinaloa, Durango and Zacatecas with the purpose of implementing this tool for the north of Mexico. Advances on the Monitoring System The monitoring system allows an analysis of the frequency, duration and intensity of the drought events that took place in several climatic regions (Núñez-López et al., 2005); un map of spatial distribution of the SPI for the northern region of Mexico, in the States of Sonora, Sinaloa, Durango and Chihuahua. The generated map will be published in a section on the CEISS web page (www.sequia.edu.mx), together with the monthly bulletin available to the public in general; it is monitoring to an annual scale, the tendencies of the deficits or surplus of the runoff volumes on three of the main dams in the State of Chihuahua Conclusions The Drought Monitoring System in Chihuahua complies with the following international rules for the

  5. An Overall Water Quality Index (WQI) for a Man-Made Aquatic Reservoir in Mexico

    OpenAIRE

    Hector Rubio-Arias; Manuel Contreras-Caraveo; Adan Pinales-Munguia; Rey Manuel Quintana; Ruben Alfonso Saucedo-Teran

    2012-01-01

    A Water Quality Index (WQI) is a useful statistical tool for simplifying, reporting and interpreting complex information obtained from any body of water. A simple number given by any WQI model explains the level of water contamination. The objective was to develop a WQI for the water of the Luis L. Leon dam located in the state of Chihuahua, Mexico. Monthly water samples were obtained in 2009; January 10, February 12, March 8, May 20, June 10, July 9, August 12, September 10, October 11, Nove...

  6. The involvement of citizens and water management: Neighborhood committees leaders in Ciudad Juárez, Chihuahua

    OpenAIRE

    Gustavo Córdova Bojórquez

    2005-01-01

    This paper seeks to analyze public participation in water management through a survey applied to the leaders of neighborhood committees in Ciudad Juarez, Chihuahua. As part of the methodology, two variables —external and internal influences— and fourteen indicators were utilized. Results show that neighborhood committees, as a public participation structure, are in crisis. The structure shows both internal and external signs of breaking up: there are no clear mechanisms of summons or particip...

  7. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  8. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-08-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  9. 1985 Mexico City, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 square km area of Mexico City, 350 km from the epicenter....

  10. Mexico Geoid Heights (MEXICO97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for Mexico, and North-Central America, is the MEXICO97 geoid model. The computation used about one million terrestrial and marine gravity...

  11. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  12. The first educational interferometer in Mexico (FEYMANS): A novel project

    Science.gov (United States)

    Villicana Pedraza, Ilhuiyolitzin; Guesten, Rolf; Saucedo Morales, Julio Cesar; Carreto, Francisco; Valdes Estrada, Erik; Wendolyn Blanco Cardenas, Monica; Rodríguez Garza, Carolina B.; Pech Castillo, Gerardo A.; Ángel Vaquerizo, Juan

    2016-07-01

    An interferometer is composed of several radio telescopes (dishes) separated by a defined distance and used in synchrony. This kind of array produces a superior angular resolution, better than the resolution achieved by a single dish of the same combined area. In this work we propose the First Educational Youth Mexican Array North South, FEYMANS. It consists of an educational interferometer with initially four dishes. This array harvests Mexico's geography by locating each dish at the periphery of the country; creating new scientific links of provincial populations with the capital. The FEYMANS project focus in high school students and their projects on physics, chemistry and astronomy as a final project. Also, it can be used for bachelor theses. The initial and central dish-node is planed to be in Mexico City. After its construction, the efforts will focus to build subsequent nodes, on the Northwest region, Northeast, or Southeast. Region Northwest will give service to Baja California, Sonora and Chihuahua states. Region Northeast will cover Coahuila, Nuevo Leon and Tamaulipas. Finally, region Southeast will give access to Yucatan, Quintana Roo, Campeche, Tabasco and Chiapas. This project has been conceived by young professional astronomers and Mexican experts that will operate each node. Also, we have the technical support of the "Max Planck Institute fuer Radioastronomy in Bonn Germany" and the educational model of the "PARTNeR" project in Spain. This interferometer will be financed by Mexico's Federal Congress and by Mexico City's Legislative Assembly (ALDF).

  13. Desarrollo forestal sustentable en Chihuahua, México: una estrategia multidimensional

    Directory of Open Access Journals (Sweden)

    Concepción Luján Álvarez

    2008-01-01

    Full Text Available Establecer una estrategia multidimensional para lograr el desarrollo forestal sustentable en la región de clima templado frío en Chihuahua, México, fue el objetivo del presente estudio, que se obtuvo con la aplicación del modelo Multiconferencia de Búsqueda (MCB, basado en el sistema de organización por asociaciones de productores forestales (ejidatarios, comuneros y pequeños propietarios, incluidos indígenas y mestizos. La metodología participativa aplicada consideró el carácter social de la propiedad de los recursos forestales en México, y se apoyó en la colaboración activa de ejidos y comunidades y demás actores relacionados. La estrategia multidimensional establecida está integrada por las dimensiones ecológicas ambientales, socioculturales, económicas, político-institucionales y científico-tecnológicas, que incluye objetivos y acciones estratégicas que consideran las necesidades e intereses comunes de los involucrados en la búsqueda del desarrollo forestal regional, con visión de sustentabilidad.

  14. Investigation of the radioactivity in air, water and soil in the Estado de Chihuahua

    International Nuclear Information System (INIS)

    The results of the determinations of activities of the series of U-238, Th-232 and the K-40 in soils, of the Rn-222 in the air of the domiciles, and in underground water are presented, as well as the total uranium activity in underground water, product of an extensive sampling in the state of Chihuahua. In two of the aquifers a positive correlation was obtained among the concentration of total uranium and the Rn-222 dissolved in the water of each well. Also it was finds a positive tendency among the averages of the concentration of U-238 in the soil and of the concentration of Rn-222 in the air of the domiciles in different towns, and among the averages of the concentration of U-238 in the floor and of the concentration of the Rn-222 dissolved in the well water in different aquifer. It is suggested that the constitution for rocks more or less uraniferous of the alluvial valleys gives explanation to the observed correlations. (Author)

  15. Groundwater Budget Analysis of Cross Formational Flow: Hueco Bolson (Texas and Chihuahua)

    Science.gov (United States)

    Hutchison, W. R.

    2005-12-01

    Groundwater from the Hueco Bolson supplies the majority of municipal water in El Paso, Texas and Ciudad Juarez, Chihuahua, the largest international border community in the world. For over 100 years, water managers and researchers have been developing an understanding of Hueco Bolson groundwater occurrence and movement, and the interaction between surface water and groundwater. Since 2001, isotopic studies of groundwater chemistry on both sides of the border have provided valuable insights into the occurrence of groundwater and its historic movement. Numerical groundwater flow models of the area have been developed and used since the 1970s. The results of the most recent model were used to develop a detailed analysis of the groundwater inflows, outflows and storage change of the entire area and subregions of the model domain from 1903 to 2002. These detailed groundwater budgets were used to quantify temporal and spatial flow changes that resulted from groundwater pumping: induced inflow of surface water, decreased natural outflows, and storage declines. In addition, the detailed groundwater budgets were used to quantify the changes in cross formational flow between the Rio Grande Alluvium and the Hueco Bolson, as well as the changes in vertical flow within the Hueco Bolson. The groundwater budget results are consistent with the results of the isotopic analyses, providing a much needed confirmation of the overall conceptual model of the numerical model. In addition, the groundwater budgets have provided information that has been useful in further interpreting the results of the isotopic analyses.

  16. Indicators for the sustainable use of water in Ciudad Juarez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Luis Ernesto Cervera Gómez

    2007-07-01

    Full Text Available This paper seeks to develop indicators that allow us to progress in the evaluation of the sustainable use of water in Ciudad Juarez, Chihuahua. In order to measure sustainability, a systematic model was proposed involving society, institutions, infrastructure and the environment that would allow us to advance in the knowledge about interaction between society and its environment. Progress was achieved in the developing and measurement of some indicators, such as those related to quality of life and current state of water infrastructure and treatment. Using existing data, it was possible to develop and measure the following indicators for the sustainable use of water: 1. secure access to water; 2. access to adequate sanitation systems; 3. domiciliary connections; 4. water price; 5. water consumption, and 6. waste water treatment. Results indicate that the municipal water system of Ciudad Juarez presents good indicators for sustainable use of water, however, they do not take into account the negative rate of rechargeextraction of the city's water supply system or of the quality of water for human consumption. The author considers that other indicators related to institutional and legal frame works, citizen participation, water quality, and environmental impact must be developed and estimated.

  17. El comercio minorista en el norte de México: agentes de Sonora y Chihuahua

    Directory of Open Access Journals (Sweden)

    Carmen O. Bocanegra Gastélum

    2004-01-01

    Full Text Available Una de las actividades económicas que actualmente se desarrolla con mayor intensidad en los estados de la frontera norte de México es el comercio de bienes de consumo personal. El tamaño del mercado que integra una población con niveles de ingreso per cápita superiores a la media nacional, además de ser territorio de cruce de mercancías en dos direcciones, lo hacen un espacio atractivo para el consumo y los agentes que se dedican al giro económico de ese tipo de comercio. El presente artículo tiene como objetivo analizar la importancia, estructura y dinámica de esa actividad en dos estados colindantes con el vecino país del norte (Chihuahua y Sonora, ofreciendo elementos cuantitativos, los institucionales que instrumenta el Estado, así como los referentes al perfil competitivo de las empresas que operan en esa región. En el trabajo se demuestra que en cada una de esas entidades se está dando una depuración de los agentes económicos del comercio a favor de empresas que provienen de estados vecinos y en contra de las nativas de los estados respectivos.

  18. A geologic and geophysic study of the Sierra de Pena Blanca, in the state of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Within the sistematic aerial exploration program realized by the Instituto Nacional de Energia Nuclear, an aeroradiometric study was carried out in the zone which includes Sierra de Pena Blanca. This study took into consideration the former and present geological investigations and compromised the sierra together with the bordering valleys. The main objective consists in the localization of areas presenting favorable conditions for the existence of uranium isotopes minerlization, in order to determine a mineralized body or ore deposit. For that purpose the area was explored with an airplane to which a differential gamma rays spectrometer was adapted, this spectrometer will show us clearly the integration of the number of radiations which fall into the detectors obtaining this way a valuable information about the radiometric anomalous sites of the studied zone and also about the existence of bismuth, thallium and the abundant potassium of the igneous rocks. These anomalies are under the stage of ground verification, this stage includes a superficial study and the study of the underlying rocks through drilling, radiometric logs and chemical analysis of the samples. In fact, through this method we can obtain very truthful data. (author)

  19. Associations between arsenic species in exfoliated urothelial cells and prevalence of diabetes among residents of Chihuahua, Mexico

    Czech Academy of Sciences Publication Activity Database

    Currier, J. M.; Ishida, M. C.; González-Horta, C.; Sánchez-Ramírez, B.; Ballinas-Casarrubias, L.; Gutiérrez-Torres, D. S.; Cerón, R. H.; Morales, D. V.; Terrazas, F. A. B.; Del Razo, L. M.; García-Vargas, G. G.; Saunders, R. J.; Drobná, Z.; Fry, R. C.; Matoušek, Tomáš; Buse, J. B.; Mendez, M. A.; Loomis, D.; Stýblo, M.

    2014-01-01

    Roč. 122, č. 10 (2014), s. 1088-1094. ISSN 0091-6765 R&D Projects: GA MŠk LH12040 Institutional support: RVO:68081715 Keywords : arsenic * speciaton analysis * diabetes Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 7.977, year: 2014

  20. Uranium and radium activities in samples of aquifers of the main cities of the Estado de Chihuahua; Actividades de uranio y radio en muestras de agua subterranea de las principales ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L.; Colmenero S, L.; Montero C, M.E. [CIMAV, Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: lourdes.villalba@cimav.edu.mx

    2003-07-01

    The natural uranium is in four valence states +3, +4, +5 and +6 being the hexavalent state the more soluble, which plays an important role in the transport of the uranium in the environment. The high concentrations of uranium in water not only in near waters to uranium mines, but also are in some mineral waters or in waters that are extracted of deep wells as it happens in the State of Chihuahua, where the underground waters are the fundamental source of consumption. The radium is a disintegration product of the uranium, the radio content in water is considered the second source of natural radioactivity. The distribution of radium in water is in function of the uranium content present in the aquifer. It was determined the uranium and radium content in samples of underground water of the main cities of the State of Chihuahua according to their number of inhabitants. The extraction methods for uranium and sulfates precipitation of Ba-Ra by means of the addition of barium carriers for the radium were used. The measures of the activities of uranium and radium were carried out by means of a portable liquid scintillation detector trade mark Thiathler-OY HIDEX. The obtained results have demonstrated that the content of uranium and radium in dissolution are in most of the sampling wells above the permissible maximum levels that manage the Mexican regulations. The high contents of uranium and radio can be attributed since to the influence of the geologic substrate characteristic of the zone in the State of Chihuahua they exist but of 50 uranium deposits. (Author)

  1. Petroleum exploration and development opportunities in Mexico

    International Nuclear Information System (INIS)

    This paper presents a historical overview of the energy sector in Mexico, an important player in the world energy market, whose trade and market policies support economic development and foreign investment. Trade, commerce and investment between Canada and Mexico has been increasing steadily ever since the North American Free Trade Agreement (NAFTA) came into effect in January 1994. TransAlta Corporation and Westcoast Energy Inc. are two very active investors in the energy sector. Westcoast has invested in increasing natural gas and oil production from the Cantarell field in the Gulf of Mexico through the Campeche Natural Gas Compression Service Project and the Cantarell Nitrogen Plant. TransAlta has invested in two natural gas fired power plants which are both expected to be in service for the second quarter of 2003. These include the 252 MW Campeche facility and the 259 MW Chihuahua facility. Mexico has proven crude oil reserves of 27 billion barrels, proven natural gas reserves of 30 tcf, and in 2000 had a crude oil production of 3.4 mmbl/d, of which half was exported. The energy sector in Mexico may need about $120 billion of investment by 2010, of which half will be used for crude oil exploration and production, transportation and refining and the other half for natural gas exploration and production, transportation and distribution and power generation. Recently, the Mexican government embarked on two initiatives. The first to increase the productivity and profitability of PEMEX, the largest corporation in Mexico and one of the largest in the world, and to allow a form of private investment in the development of non-associated natural gas fields. This paper discussed the significance of the Multiple Service Contracts (MSC) program which involves domestic and international petroleum exploration and development. It also discussed forms of business organizations, taxation and structuring, financial issues, employment and the North American Free Trade Agreement

  2. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  3. Uranium and radium activities in samples of aquifers of the main cities of the Estado de Chihuahua

    International Nuclear Information System (INIS)

    The natural uranium is in four valence states +3, +4, +5 and +6 being the hexavalent state the more soluble, which plays an important role in the transport of the uranium in the environment. The high concentrations of uranium in water not only in near waters to uranium mines, but also are in some mineral waters or in waters that are extracted of deep wells as it happens in the State of Chihuahua, where the underground waters are the fundamental source of consumption. The radium is a disintegration product of the uranium, the radio content in water is considered the second source of natural radioactivity. The distribution of radium in water is in function of the uranium content present in the aquifer. It was determined the uranium and radium content in samples of underground water of the main cities of the State of Chihuahua according to their number of inhabitants. The extraction methods for uranium and sulfates precipitation of Ba-Ra by means of the addition of barium carriers for the radium were used. The measures of the activities of uranium and radium were carried out by means of a portable liquid scintillation detector trade mark Thiathler-OY HIDEX. The obtained results have demonstrated that the content of uranium and radium in dissolution are in most of the sampling wells above the permissible maximum levels that manage the Mexican regulations. The high contents of uranium and radio can be attributed since to the influence of the geologic substrate characteristic of the zone in the State of Chihuahua they exist but of 50 uranium deposits. (Author)

  4. PERSPECTIVAS DEL SISTEMA DE PRODUCCIÓN DE MANZANO EN CHIHUAHUA, ANTE EL CAMBIO CLIMÁTICO

    OpenAIRE

    Manuel Rafael Ramírez Legarreta; José Ariel Ruiz Corral; Guillermo Medina García; Juan Luis Jacobo Cuéllar; Rafael Ángel Parra Quezada; Mario René Ávila Marioni; Jesús Pilar Amado Álvarez

    2011-01-01

    El ensayo es un intento de estimar desde el punto de vista fenológico, ambiental y socioeconómico el efecto del cambio climático sobre el sistema de producción de manzano en el estado de Chihuahua, México. Se reanalizaron datos de clima, fenología y socioeconómicos con una antigüedad de más de 10 años en periodos diferentes, contextualizando éstos bajo el entorno actual del calentamiento global. Los resultados obtenidos indican tendencias claras en el incremento de los costos de producción, l...

  5. Participación ciudadana en las colonias sin agua potable y alcantarillado de Ciudad Juárez, Chihuahua

    OpenAIRE

    Gustavo Córdova Bojórquez; Ma. de Lourdes Romo Aguilar

    2007-01-01

    En este artículo se presenta un análisis de la participación ciudadana en la gestión del agua en 14 colonias que carecen del servicio de agua potable y alcantarillado en Ciudad Juárez, Chihuahua. La metodología consistió en analizar y relacionar las influencias externas e internas de los ciudadanos resultando una participación ciudadana muy baja en la gestión del agua determinada en gran medida por el poco conocimiento sobre el tema, la poca confianza en las instituciones públicas, la mínima ...

  6. La violencia en la región noroeste de Chihuahua. Experiencias e impactos desde la comunidad educativa

    OpenAIRE

    Estrada Ruiz, Marcos J.; Adán Cano Aguilar

    2013-01-01

    La violencia escolar ha sido un tema explorado de manera importante en los últimos años desde la investigación educativa en México, sin embargo, en contextos de alta violencia no se han mostrado los impactos de la violencia extraescolar y estructural, en la escuela y en otros espacios comunitarios. El artículo presenta resultados de una investigación que tuvo por objetivo reconstruir el impacto de la violencia en la región noroeste de Chihuahua, desde la comunidad educativa (docentes, padres,...

  7. Numerical analysis of a proposed percolation experiment at the Pena Blanca natural analog site

    International Nuclear Information System (INIS)

    A field-scale percolation test is proposed for the Pena Blanca natural analog site near Chihuahua, MX. To aid in design of the field test, the V-TOUGH two-phase flow simulator was applied to model percolation of water through 8 to 10 m of partially saturated fractured tuff. The rock was characterized as a composite medium using measured hydraulic properties for the rock matrix and estimated values for the fractures. Measured matrix permeability varied over four orders of magnitude and fracture apertures were estimated to range from 10 to 1,000 μm. Water arrival times were predicted to vary between one day to 10,000 yr. The utility of the composite model and other representations of flow through fractured porous media can be tested using results from the field scale infiltration test data

  8. Distribution of heat flow and radioactive heat generation in northern Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.L.; Nuckels, C.E. III; Jones, R.L.; Cook, G.A.

    1979-05-10

    Twenty-five new heat flow measurements from northern Mexico range from 0.6 HFU (1 HFU = 1 ..mu..cal/cm/sup 2/s = 41.8 mW/m/sup 2/) at Los Plomosas, Chihuahua, to 4.2 HFU about 30 km east of Mazatlan, Sinaloa. The new values, in conjunction with previous data, confirm the Baja peninsula as an area of low to normal heat flow and demonstrate an irregular decrease of heat flow eastward from the Gulf of California across the Sierra Madre Occidental and a separate pattern of decreasing heat flow eastward from the Central Plateau across the Sierra Madre Oriental. An area of high heat flow immediately east of the Gulf of California is identified and is tentatively related to the spreading ridges in the gulf. Abundances of the radioactive-heat-generating elements uranium, thorium, and potassium increase from Baja California to the eastern border of the Sierra Madre Occidental, abruptly decrease within the Central Plateau, and then increase again eastward through the Sierra Madre Oriental. Although a general positive correlation between heat flow and radioactive heat generation is observed, adherance to the expected linear patterns cannot be demonstrated. This lack of linearity prohibits the definition of separate thermal provinces in northern Mexico and suggests the assignment of the Sierra Madre Occidental as a southerly extension of the Basin and Range thermal province that is modified by sea floor spreading in the Gulf of California. Heat flow measurements in the states of Chihuahua, Durango, and Zacatecas are similar to those associated with the Rio Grande Rift thermal anomaly in New Mexico, but an indentification of a continuous extension of the rift thermal conditions into northern Mexico cannot be made.

  9. Natural Analogs for the Unsaturated Zone

    International Nuclear Information System (INIS)

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model

  10. NaturAnalogs for the Unsaturated Zone

    Energy Technology Data Exchange (ETDEWEB)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  11. Prevalencia de desnutrición en niños tarahumaras menores de cinco años en el municipio de Guachochi, Chihuahua Prevalence of malnutrition in Tarahumara children under 5 years of age in the municipality of Guachochi, Chihuahua

    Directory of Open Access Journals (Sweden)

    Joel Monárrez

    2000-02-01

    Full Text Available OBJETIVO: Determinar la prevalencia de desnutrición en niños tarahumaras menores de cinco años en el municipio de Guachochi, Chihuahua, México. MATERIAL Y MÉTODOS: Durante el verano de 1996, fueron muestreados 450 niños, representativos de 62 comunidades, estratificadas por el tamaño de su población. La muestra representa 12.2% del total de tarahumaras del municipio. Para cada uno de los índices antropométricos peso/edad, peso/talla y talla/edad se calculó la desviación en puntaje Z de cada observación de la mediana de la población de referencia (NCHS. Se presentan medias y desviaciones estándar de las mediciones realizadas, así como la prevalencia de desnutrición, estratificada por edad, sexo y tamaño de la localidad de residencia de los niños. RESULTADOS: Las prevalencias de desnutrición a ±DE:-1.66±1.1; peso/talla: 3.5% (±DE: -0.43±0.9 y; talla/edad: 57.1% (±DE: -2.15±1.3. Los niños de 12-23 meses de edad fueron los más afectados (OBJECTIVE: To determine the prevalence of malnutrition among Tarahumara children under 5 years of age in the municipality of Guachochi, Chihuahua, Mexico. MATERIAL AND METHODS: During the summer of 1996, we interviewed a representative sample of 450 children from 62 communities, stratified by size of population. The sample represents 12.2% of the total number of Tarahumaras in the municipality. For each of three anthropometric indices (weight-for-age, weight-for-height and height-for-age, we calculated the Z-score in reference to NCHS population values. Results are presented as means and standard deviations as well as prevalence of malnutrition at different cut-off-points, stratified by age, sex, and size of the community. RESULTS: Prevalence figures of malnutrition (<-2Z were: weight-for-age: 36.4% (mean SD± -1.66 ±1.1; weight-for-height: 3.5% (mean SD± -0.43 ±0.9; and height-for-age: 57.1% (mean SD± -2.15 ±1.3. Children aged 12-23 months were the most affected, both in weight

  12. Insulin analogs and cancer

    Directory of Open Access Journals (Sweden)

    Laura eSciacca

    2012-02-01

    Full Text Available Today, insulin analogs are used in millions of diabetic patients. Insulin analogs have been developed to achieve more physiological insulin replacement in terms of time course of the effect. Modifications in the amino acid sequence of the insulin molecule change the pharmacokinetics and pharmacodynamics of the analogs in respect to human insulin. However, these changes can also modify the molecular and biological effects of the analogs. The rapid-acting insulin analogs, lispro, aspart and glulisine, have a rapid onset and shorter duration of action. The long-acting insulin analogs glargine and detemir have a protracted duration of action and a relatively smooth serum concentration profile. Insulin and its analogs may function as growth factors and therefore have a theoretical potential to promote tumor proliferation. A major question is whether analogs have an increased mitogenic activity in respect to insulin. These ligands can promote cell proliferation through many mechanisms like the prolonged stimulation of the insulin receptor, stimulation of the IGF-1 receptor (IGF-1R, prevalent activation of the ERK rather than the AKT intracellular post-receptor pathways. Studies on in vitro models indicate that short-acting analogs elicit molecular and biological effects that are similar to those of insulin. In contrast, long-acting analogs behave differently. Although not all data are homogeneous, both glargine and detemir have been found to have a decreased binding to IR but an increased binding to IGF-1R, a prevalent activation of the ERK pathway, and an increased mitogenic effect in respect to insulin. Recent retrospective epidemiological clinical studies have suggested that treatment with long-acting analogs (specifically glargine may increase the relative risk for cancer. Results are controversial and methodologically weak. Therefore prospective clinical studies are needed to evaluate the possible tumor growth-promoting effects of these insulin

  13. The Analogical Mind

    OpenAIRE

    Holyoak, Keith J.; Thagard, P.

    1997-01-01

    We examine the use of analogy in human thinking from the perspective of a multiconstraint theory, which postulates three basic types of constraints: similarity, structure and purpose. The operation of these constraints is apparent in both laboratory experiments on analogy and in naturalistic settings, including politics, psychotherapy, and scientific research. We sketch how the multiconstraint theory can be implemented in detailed computational simulations of the analogical human mind.

  14. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  15. Análisis de la periodicidad del viento con FFT en el estado de Chihuahua. México

    Directory of Open Access Journals (Sweden)

    Quetzalcoatl Cruz Hernández-Escobedo

    2011-07-01

    Full Text Available El viento puede ser una gran fuente de energía renovable, por ello el conocimiento exhaustivo de su comportamiento es de especial importancia a la hora de abordar cualquier proyecto que contemple su empleo. En el presente trabajo se aplican las técnicas de análisis espectral, mediante la aplicación de la Transformada Rápida de Fourier (FFT, que es una herramienta que permite conocer los diferentes componentes de periodicidad que puedan existir en un fenómeno considerado de tipo periódico y en su caso descubrir si lo es o no. Las variables analizadas fueron la velocidad y dirección del viento, con un periodo de retorno de 2 años, con datos cada 10 minutos, de 23 estaciones meteorológicas del estado de Chihuahua, México. Los resultados obtenidos fueron principalmente dos: 1.157E-005Hz y 2.315E-005Hz, es decir, el estado de Chihuahua cuenta con una periodicidad del viento cada 24 y 12 horas respectivamente, esto es importante para la evaluación del recurso eólico. 

  16. Analog synthetic biology.

    Science.gov (United States)

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations. PMID:24567476

  17. Microenvironmental air and soil monitoring of contaminants: An evaluation of indoor and outdoor levels in Chihuahua City

    Science.gov (United States)

    Delgado-Rios, Marcos

    Like most of the cities around the world Chihuahua City suffers atmospheric and soil pollution. This is a problem that requires immediate attention from both public authorities and the scientific community. Although it is known that high levels of heavy metals are present in the airborne particulate matter, soil and dust in many urban regions, the information about personal exposure to these pollutants in Chihuahua City is nonexistent. This study focuses on the analysis and characterization of lead and arsenic in the airborne and soil particulate matter present in the interiors of households and their surrounding outdoor environments in the southern part of Chihuahua City. The sampling area chosen for this study was located in the southern part of Chihuahua City. An atmospheric sampling point selected by the Centro de Investigacion en Materiales Avanzados (CIMAV) was selected as a geographical center, with a 2 km radius forming the sampling area. The households selected for analyses were located on Lombardo Toledano Street, a high-traffic street. The main objectives of this study were to establish the maximum exposure level in outdoor and indoor environments for particulate matter less than 10 mum (PM 10), Pb, and As, to determine the background level of Chihuahua City for these same elements, to determine the isotopic ratios of Pb206 and Pb207 in the indoor and outdoor atmospheric samples, and to verify if the source of the pollution is from anthropogenic and/or natural sources. Additionally, a comparison of the analytical data from X-ray fluorescence (XRF) versus the analytical data from inductively coupled plasma with optical emission spectroscopy (ICP-OES) was conducted. The comparison of these techniques was based on sample preparation, speed of analysis, and accuracy of results. In the case of sample preparation, two extraction techniques were performed for a comparison of the extraction/leaching of Pb and As from the samples. These microwave

  18. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  19. Analog pulse processor

    Science.gov (United States)

    Wessendorf, Kurt O.; Kemper, Dale A.

    2003-06-03

    A very low power analog pulse processing system implemented as an ASIC useful for processing signals from radiation detectors, among other things. The system incorporates the functions of a charge sensitive amplifier, a shaping amplifier, a peak sample and hold circuit, and, optionally, an analog to digital converter and associated drivers.

  20. Egade, Mexico.

    Science.gov (United States)

    Kubany, Elizabeth

    2001-01-01

    Presents a business school design in Mexico, whose spiral building sits atop a parking structure creating a compact, symbolic form for an arid urban landscape. Includes seven photographs, a floor plan, and sectional drawing. (GR)

  1. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers. PMID:24915320

  2. VNIR reflectance spectra of gypsum mixtures for comparison with White Sands National Monument, New Mexico (WSNM) dune samples as an analog study of the Olympia Undae region of Mars

    Science.gov (United States)

    King, S. J.; Bishop, J. L.; Fenton, L. K.; Lafuente, B.; Garcia, G. C.; Horgan, B. H.

    2013-12-01

    Dunes at WSNM are being used as an analog study area for gypsum-rich dunes near the northern polar region of Mars. Samples were collected from 4 dunes at WSNM for this study. In order to determine abundances of the gypsum, quartz and dolomite present in the dune sand, size separates (250 μm) were prepared for gypsum, quartz and dolomite, mixtures were prepared using the 90-150 μm size fraction, and all samples were characterized in the lab. Analyses of the VNIR spectral data are presented here (Figs. 1-2) and analyses of the XRD data are presented in a companion abstract [1]. The majority of the dune sand is dominated by gypsum, while the coarse grains at some ripples are largely dolomite. Mid-IR spectra will be evaluated as well. Gypsum/Dolomite Mixtures (Fig. 1) There is a clear progression of albedo and band strength in these mixture spectra as one mineral is increased and the other decreased. The mixture spectra are dominated by the gypsum bands for mixtures that are gypsum rich (≥50wt.% gypsum) including a triplet at 1.446-1.535 μm, plus bands at 1.749, 1.945, 2.217 and 2.267 μm. When mixtures become predominantly dolomite (10/90 & 20/80 mixtures), the gypsum bands are significantly weaker, while the dolomite band at 2.322 becomes much more visible. Gypsum/Quartz Mixtures (Fig. 2) The gypsum/quartz mixture spectra are dominated to an even greater extent by gypsum, resulting in readily observable gypsum features for spectra of samples with only 10 wt.% gypsum. [1] Lafuente et al. (2013) AGU, submitted.

  3. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  4. Challenges in Analogical Reasoning

    CERN Document Server

    Lin, Shih-Yin

    2016-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same physics principle is involved but that is more difficult to handle. Here, we examine introductory physics students' ability to use analogies in solving problems involving Newton's second law. Students enrolled in an algebra-based introductory physics course were given a solved problem involving tension in a rope and were then asked to solve another problem for which the physics is very similar but involved a frictional force. They were asked to point out the similarities between the two problems and then use the analogy to solve the friction problem.

  5. TV Analog Station Transmitters

    Data.gov (United States)

    Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Analog Television Stations (see Rule Part47 CFR...

  6. Mental health outcomes of Mexico's drug war in Ciudad Juárez: A pilot study among university students.

    Science.gov (United States)

    O'Connor, Kathleen; Vizcaino, Maricarmen; Benavides, Nora A

    2014-03-01

    During the most intense period of armed conflict related to the drug trade in Mexico, forty students attending the Universidad Autónoma de Ciudad Juárez (UACJ) in Ciudad Juárez, Chihuahua, Mexico, were surveyed in this pilot study for symptoms of depression, anxiety and post-traumatic stress using the Harvard Trauma Questionnaire and the Hopkins Symptom Checklist. The percentage of participants who scored positively for symptoms of PTSD depression and anxiety were 32.5%, 35% and 37.5%, respectively. Criteria for post-traumatic stress were analyzed separately. The most frequently-reported traumatic events included extortion or robbery, confinement to home, injury to loved one, being in an armed conflict, witnessing a killing or dead body and being beaten. Trauma events positively associated with depression, anxiety and PTSD symptoms included robbery or extortion, armed conflict situation, exposure to frequent arms fire, and witnessing a killing or dead body. PMID:25110466

  7. Participación ciudadana en las colonias sin agua potable y alcantarillado de Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Gustavo Córdova Bojórquez

    2007-01-01

    Full Text Available En este artículo se presenta un análisis de la participación ciudadana en la gestión del agua en 14 colonias que carecen del servicio de agua potable y alcantarillado en Ciudad Juárez, Chihuahua. La metodología consistió en analizar y relacionar las influencias externas e internas de los ciudadanos resultando una participación ciudadana muy baja en la gestión del agua determinada en gran medida por el poco conocimiento sobre el tema, la poca confianza en las instituciones públicas, la mínima disposición de participar en proyectos comunitarios y por la gran influencia que tiene el sistema político en la gestión del servicio.

  8. The involvement of citizens and water management: Neighborhood committees leaders in Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Gustavo Córdova Bojórquez

    2005-07-01

    Full Text Available This paper seeks to analyze public participation in water management through a survey applied to the leaders of neighborhood committees in Ciudad Juarez, Chihuahua. As part of the methodology, two variables —external and internal influences— and fourteen indicators were utilized. Results show that neighborhood committees, as a public participation structure, are in crisis. The structure shows both internal and external signs of breaking up: there are no clear mechanisms of summons or participation, nor are there any adecuate mechanisms capable of articulating demands and government authority, insofar as external political agents have been allowed to participate in internal management and committee issues. For this reason, the capacity of local neighborhood committees to make decisions regarding city water management is placed in doubt.

  9. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  10. Synthesis of Paclitaxel Analogs

    OpenAIRE

    Xu, Zhibing

    2010-01-01

    Paclitaxel is one of the most successful anti-cancer drugs, particularly in the treatment of breast cancer and ovarian cancer. For the investigation of the interaction between paclitaxel and MD-2 protein, and development of new antagonists for lipopolysaccharide, several C10 A-nor-paclitaxel analogs have been synthesized and their biological activities have been evaluated. In order to reduce the myelosuppression effect of the paclitaxel, several C3â ² and C4 paclitaxel analogs have been synth...

  11. Evaluación de la propuesta de intervención para estudiantes sobresalientes: caso Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Covarrubias Pizarro, Pedro

    2015-09-01

    Full Text Available Este artículo tiene como propósito exponer los resultados de un trabajo de investigación evaluativa realizado para valorar la implementación de la Propuesta de Intervención Educativa para alumnos y alumnas con Aptitudes Sobresalientes, puesta en marcha por la Secretaría de Educación Pública de México durante el ciclo escolar 2007-2008. Para evaluar dicha propuesta, se diseñó y aplicó un modelo conformado por cuatro componentes, cuatro criterios y trece descriptores. Para la recuperación de los datos y su análisis correspondiente, se empleó una metodología de corte mixto que consideró diferentes momentos, actores e instrumentos. En este documento se presenta el trabajo realizado mediante el enfoque cualitativo, destacando los resultados obtenidos en los grupos de discusión y las entrevistas semiestructuradas. El estudio se llevó a cabo en el estado de Chihuahua, México y participaron como informantes significativos el personal de educación especial del subsistema estatal del estado de Chihuahua, padres y madres de familia de estudiantes sobresalientes, maestras de grupo regular, alumnado identificado como sobresaliente y personas expertas en el tema de las altas capacidades. Los resultados apuntan que la propuesta de intervención valorada cuenta con cualidades relacionadas con su fundamento teórico y metodológico, sin embargo, la mayor debilidad se ubica en la operatividad, aspecto que puede ser sujeto a mejorar para la obtención de mayores resultados en la intervención.

  12. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  13. Possible Scenarios of Impacts of Climatic Change on Potential Evapotranspiration in the Watershed of the Conchos River, Mexico

    Science.gov (United States)

    Raynal-Villasenor, J. A.; Rodriguez-Pineda, J. A.

    2007-12-01

    The watershed of the Conchos River is the main watershed of the state of Chihuahua, Mexico, and it is the main source of water of the watershed of the Grande river downstream El Paso, Texas. Such part of the watershed of the Grande River is also the border between Mexico and the United States of America, from El Paso-Ciudad Juarez up to Brownsville-Matamoros. It is very important for the state of Chihuahua and Mexico as a whole, to construct possible scenarios of the effects of the global climatic change in the potential evapotranspiration in such watershed and to construct likely scenarios which results will help to define an integrated watershed management to mitigate those global climate change impacts. The results of a recent study sponsored by the alliance between WWF-Fundacion Gonzalo Rio Arronte, are presented in the paper. The study was conducted to construct possible scenarios on the effects of the global climatic change on the potential evapotranspiration in the watershed of the Conchos River in Mexico. Three watershed characteristic meteorological stations were selected to conduct such study. The predictions of change of the surface air temperature and the change of the rainfall produced by the global climatic change, by the end of the XXI Century, were those published by the Hadley Center. The results show that air temperature increment of one degree centigrade increases evapotranspiration values between 3 and 3.5% with respect current values. As a consequence moisture deficiency increases from 9% to 40%. With an air temperature increment of three degrees centigrades, the potential evapotranspiration increases between 8.8% and 10% increasing moisture deficiency from 27.5% up to 116%. The expected rainfall increment values show a negligible contribution for the potential evapotranspiration reduction in the Rio Conchos watershed. These results conclude that immediate actions need to be taken to mitigate climate change impacts all along the watershed.

  14. Conmemoraciones históricas, activación y posicionamiento turístico: Centenario, Bicentenario y Tricentenario en Chihuahua

    Directory of Open Access Journals (Sweden)

    Anna María Fernández Poncela

    2011-01-01

    Full Text Available Este texto es una revisión y reflexión sobre algunos conceptos y fenómenos sociales con relación al patrimonio cultural, las conmemoraciones históricas y el turismo cultural. El estudio de caso es la triple celebración en Chihuahua, Centenario de la Revolución Mexicana, Bicentenario de la Independencia de México y Tricentenario de la fundación de la ciudad capital del estado de Chihuahua. Con este ejemplo, se observa cómo se reproduce y consume la identidad nacional, el patrimonio histórico y cultural -tangible e intangible- y cómo el turismo consume identidad y patrimonio. Desde el presente exaltamos el pasado y proyectamos expectativas hacia el futuro.

  15. Niveles de contaminación del agua potable en la cabecera municipal de Ascención, Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Héctor Osbaldo Rubio Arias

    2015-01-01

    Full Text Available Introducción: El agua es una sustancia indispensable para la vida por lo que se considera como el recurso natural más apreciado en el planeta. En el norte de México existe el “Programa ambiental México-Estados Unidos: Frontera 2020”; en el cual participan instituciones mexicanas como la Junta Municipal de Aguas y Saneamiento (JMAS mientras que por parte de los Estados Unidos de Norteamérica participan el Taskforce U.S., la Agencia Ambiental (USEPA y la Universidad Estatal de Nuevo Mexico, entre otras (PAMEUF, 2013. En dicho programa ambiental el municipio de Ascensión está contemplado dentro de los planes de acción, por ser una región fronteriza, en especial en lo relacionado a la meta 2, la cual especifica el suministro de agua limpia y segura. Es importante mencionar que, a la fecha, no se conoce información que permita evaluar el nivel de calidad que aportan los cinco pozos que surten de agua a la cabecera municipal de Ascención, Chihuahua. El objetivo fue evaluar la calidad del agua potable que utiliza la comunidad de Ascensión, Chihuahua, mediante análisis físico-químico-metales y microbiológicos. Método: Las muestras de agua se obtuvieron de cinco pozos y de cinco hogares seleccionados al azar en cuatro temporadas. Se realizaron cuatro muestreos; julio de 2011, septiembre de 2011, diciembre de 2011 y mayo de 2012. Por lo tanto, se analizaron un total de 40 muestras a las que se les cuantificó el potencial de hidrógeno (pH, conductividad eléctrica (CE, temperatura (T, oxígeno disuelto (OD, turbidez (Tur, sólidos totales (SDT, coliformes totales (CT, coliformes fecales (CF y los siguientes metales; Al, As, B, Cd, Ca, Cu, Cr, Fe, Mg, Mn, Ni, Ag, Pb, K, Na, Se, Si y Zn. Se aplicó un ANOVA para buscar diferencias por estación (Factor A, por fuente (Factor B y su interacción (AxB. Para la variable de coliformes se aplicó la prueba noparamétrica de Kruskal-Wallis. En todos los casos se consideró un nivel de

  16. Injertos en chiles tipo Cayene, jalapeño y chilaca en el noroeste de Chihuahua, México Grafting in Cayenne, jalapeño and chilaca chili peppers in northwestern Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Pedro Osuna-Ávila

    2012-07-01

    Full Text Available En semillas cosechadas por los agricultores se estudió la influencia en la sincronización de los diámetros de tallos en injertos comunes y recíprocos utilizando los tipos de chiles, jalapeño, chilaca y Cayene como injertos y el criollo de Morelos CM-334 como portainjerto. El grosor del tallo del CM 334 presentó mayor compatibilidad con el chile tipo jalapeño y con el tipo chilacay fue muy distante con el grosor del tallo del tipo de chile Cayene. La formación de callo abundante entre la unión de los injertos ensayados mostró buena aptitud y afinidad lo cual permitió la conexión firme del cambium con el patrón. Los porcentajes de supervivencia de los injertos fueron 90% con los chiles lo cual está dentro del rango aceptable a nivel comercial. El usar el CM 334 como un portainjerto resistente a P .capsici podría formar parte del manejo integrado para controlar la marchitez en estos tipos de chiles comerciales. El injerto reciproco puede ser usado para estudiar genes asociados con procesos de regulación de señales a distancia capaces de moverse de la raíz al brote como ramificaciones, floración, resistencia sistémica y respuestas a estrés abiótico.In seeds harvested by farmers, the influence on the timing of the diameters of stems was studied in common and reciprocal grafts using chilies, jalapeño, chilaca and Cayenne as grafts and, landrace Morelos CM-334 as the rootstock. CM 334's stem diameter showed high compatibility with jalapeño and chilaca, and was very distant with Cayenne. Abundant callus formation between the unions of the tested grafts showed good aptitude and affinity which allowed the firm connection of the vascular cambium. The rates of graft survival were of 90% with chilies, which is within the acceptable range for commercially purposes. Using CM 334 as a rootstock resistant to P. capsici could be part of an integrated control for wilt in these types of commercial chilies. The reciprocal graft can be used to study genes associated with regulatory processes of signais able to move from the roots to the sprout, such as branching, flowering, systemic resistance and abiotic stress responses.

  17. Injertos en chiles tipo Cayene, jalapeño y chilaca en el noroeste de Chihuahua, México Grafting in Cayenne, jalapeño and chilaca chili peppers in northwestern Chihuahua, Mexico

    OpenAIRE

    Pedro Osuna-Ávila; Julio Aguilar-Solís; Sylvia Fernández-Pavia; Heriberto Godoy-Hernández; Baltazar Corral-Díaz; Juan Pedro Flores-Margez; Alberto Borrego Ponce; Evangelina Olivas

    2012-01-01

    En semillas cosechadas por los agricultores se estudió la influencia en la sincronización de los diámetros de tallos en injertos comunes y recíprocos utilizando los tipos de chiles, jalapeño, chilaca y Cayene como injertos y el criollo de Morelos CM-334 como portainjerto. El grosor del tallo del CM 334 presentó mayor compatibilidad con el chile tipo jalapeño y con el tipo chilacay fue muy distante con el grosor del tallo del tipo de chile Cayene. La formación de callo abundante entre la unión...

  18. Real-time PCR genotyping assay for canine progressive rod-cone degeneration and mutant allele frequency in Toy Poodles, Chihuahuas and Miniature Dachshunds in Japan.

    Science.gov (United States)

    Kohyama, Moeko; Tada, Naomi; Mitsui, Hiroko; Tomioka, Hitomi; Tsutsui, Toshihiko; Yabuki, Akira; Rahman, Mohammad Mahbubur; Kushida, Kazuya; Mizukami, Keijiro; Yamato, Osamu

    2016-04-01

    Canine progressive rod-cone degeneration (PRCD) is a middle- to late-onset, autosomal recessive, inherited retinal disorder caused by a substitution (c.5G>A) in the canine PRCD gene that has been identified in 29 or more purebred dogs. In the present study, a TaqMan probe-based real-time PCR assay was developed and evaluated for rapid genotyping and large-scale screening of the mutation. Furthermore, a genotyping survey was carried out in a population of the three most popular breeds in Japan (Toy Poodles, Chihuahuas and Miniature Dachshunds) to determine the current mutant allele frequency. The assay separated all the genotypes of canine PRCD rapidly, indicating its suitability for large-scale surveys. The results of the survey showed that the mutant allele frequency in Toy Poodles was high enough (approximately 0.09) to allow the establishment of measures for the prevention and control of this disorder in breeding kennels. The mutant allele was detected in Chihuahuas for the first time, but the frequency was lower (approximately 0.02) than that in Toy Poodles. The mutant allele was not detected in Miniature Dachshunds. This assay will allow the selective breeding of dogs from the two most popular breeds (Toy Poodle and Chihuahua) in Japan and effective prevention or control of the disorder. PMID:26549343

  19. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  20. Analogical Reasoning in Geometry Education

    Science.gov (United States)

    Magdas, Ioana

    2015-01-01

    The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

  1. Electrical analogous in viscoelasticity

    Science.gov (United States)

    Ala, Guido; Di Paola, Mario; Francomano, Elisa; Li, Yan; Pinnola, Francesco P.

    2014-07-01

    In this paper, electrical analogous models of fractional hereditary materials are introduced. Based on recent works by the authors, mechanical models of materials viscoelasticity behavior are firstly approached by using fractional mathematical operators. Viscoelastic models have elastic and viscous components which are obtained by combining springs and dashpots. Various arrangements of these elements can be used, and all of these viscoelastic models can be equivalently modeled as electrical circuits, where the spring and dashpot are analogous to the capacitance and resistance, respectively. The proposed models are validated by using modal analysis. Moreover, a comparison with numerical experiments based on finite difference time domain method shows that, for long time simulations, the correct time behavior can be obtained only with modal analysis. The use of electrical analogous in viscoelasticity can better reveal the real behavior of fractional hereditary materials.

  2. Mexico's Oxbridge.

    Science.gov (United States)

    Haussman, Fay

    1979-01-01

    For 400 years the National Autonomous University of Mexico has remained at the hub of the country's intellectual and political life. The history of the University from the Mayas and the Aztecs, University expansion, upward mobility of students, and student pressure groups and politics are described. (MLW)

  3. Prevalencia de asma y otras enfermedades alérgicas en niños escolares de Ciudad Juárez, Chihuahua Prevalence of asthma and other allergic diseases in school children in Ciudad Juarez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Albino Barraza-Villarreal

    2001-10-01

    Full Text Available Objetivo. Determinar la prevalencia y severidad del asma, de la rinitis y del eczema en escolares. Material y métodos. Estudio transversal efectuado entre abril de 1998 y mayo de 1999 en Ciudad Juárez, Chihuahua, México, a una muestra aleatoria de 6 174 niños de 53 escuelas. Se aplicó la metodología propuesta por el International Study of Asthma and Allergies in Childhood (ISAAC (etapas 1 y 2 para determinar la prevalencia y severidad del asma, rinitis y eczema. La información de prevalencia, tanto actual como acumulada para dichos padecimientos, se obtuvo mediante un cuestionario ya estandarizado y contestado por los padres de los niños. El diseño de la muestra se hizo por un muestreo mixto, en el cual se estratificó por nivel de contaminación ambiental. Se estimaron prevalencias actual y acumulada estratificando por grupo de edad, sexo, área e historia familiar de asma. Resultados. La prevalencia acumulada de asma por diagnóstico médico y sibilancia (silbidos fue de 6.8% (IC95% 6.2-7.4 y 20.% (IC95% 19.7-21.8, respectivamente; la prevalencia de sibilancia en los últimos 12 meses fue mayor en el grupo de 6-8 años que en el de 11-14 años(9.7% contra 5.8% (phttp://www.insp.mx/salud/index.htmlObjective. To assess the prevalence and severity of asthma and allergic diseases in schoolchildren residing in Ciudad Juarez, Chihuahua. Material and Methods. A cross-sectional study was conducted from April 1998 to May 1999, among 6 174 children from 53 schools in Ciudad Juarez, Chihuahua. The method used was the one recommended by the International Study of Asthma and Allergies in Childhood (ISAAC to determine the prevalence and severity of asthma, rhinitis, and eczema. Parents were asked to answer a standardized questionnaire on current and cumulative prevalence of asthma, rhinitis, and eczema. A sample stratified by level of pollution was selected. Results. The cumulative prevalence of medically diagnosed asthma and wheezing was 6.8% (95

  4. Navigator Approach to Improve Quality of Care for Vulnerable Populations in Mexico.

    Science.gov (United States)

    Ramos, Rebeca; Ferreira-Pinto, João; Loza, Oralia

    2015-01-01

    For nearly 30 years, Programa Compañeros Inc (Compañeros) has worked in Ciudad Juarez, Chihuahua, Mexico, to ensure that vulnerable populations can exercise their rights to receive HIV and substance abuse prevention and treatment services. Compañeros staff has worked to ameliorate the negative results that limit access to care to the most vulnerable individuals: those who are poor, homeless, sex workers, addicted, and others whose life context put them at greater risk for being infected with HIV. With support from the MAC AIDS Foundation, Compañeros has expanded its capacity to deliver services to persons living with HIV/AIDS (PLWHA) and to HIV-vulnerable populations. This short communication describes findings from an internal evaluation conducted to investigate the effectiveness of the MAC AIDS-funded navigator-based program implemented at Compañeros. PMID:26242198

  5. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  6. Towards analogy in toponyms

    Czech Academy of Sciences Publication Activity Database

    Štěpán, Pavel

    Cluj : Mega, 2013 - (Felecan, O.), s. 379-383 ISBN 978-606-543-343-4. [Name and Naming /2./ Onomastics in Contemporary Public Space. Baia Mare (RO), 09.05.2013-11.05.2013] R&D Projects: GA ČR GPP406/12/P600 Institutional support: RVO:68378092 Keywords : onomastics * toponyms * analogy Subject RIV: AI - Linguistics

  7. Impact of climatic change in forests and natural protected areas of Mexico; Impacto del cambio climatico en los bosques y areas naturales protegidas de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villers-Ruiz, L.; Trejo-Vazquez, I. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Geografia

    1998-01-01

    The vulnerability of Mexico`s forest ecosystems to climate change was assessed according to the results of two General Circulating Models (GCMs): CCCM and GFDL-R30. Holdridge`s life zones classification was used for the analysis. The paper shows the climatic differences for each model and for different region of Mexico. Climate scenarios were compared to current climate so as to recognise climate change regions for each model. Of the 18 life zones reported for the country, the most affected ones would be the temperate cold and warm forests, tending to disappear. On the contrary, tropical dry, very dry and thorn forests with warm affinities tend to widen their current surfaces, according to the CCCMN model. The GFDL-R30 model foresees increases in the distribution of tropical, humid and wet forests, which would be favored by the increase in rainfall, giving place to tropical rain forests, currently non-existent in the country. Of the 33 natural protected areas used for this study, 24 show changes in their life zones, the most affected ones are those found in the northern and occidental regions of the country. The most affected forest industries would be those located in the Sierra Madre Occidental, in the states of Durango and Chihuahua, and to the occidental part of the country, the industries found in Michoacan and Jalisco. 36 refs., 5 figs., 4 tabs.

  8. Mexico - PROGRESA

    OpenAIRE

    IFPRI

    2002-01-01

    For many of the world's poor, public safety-net programs are the only hope for a life free from chronic poverty and undernutrition. But the proper combination of incentives and support can be difficult to achieve. The International Food Policy Research Institute's in-depth evaluation of Mexico's PROGRESA (Programa de Educación, Salud y Alimentación) indicates that antipoverty programs that combine education, health, and nutrition interventions in one package can be quite successful in improvi...

  9. The Role of Science in Advising the Decision Making Process: A Pathway for Building Effective Climate Change Mitigation Policies in Mexico at the Local Level.

    Science.gov (United States)

    Barraza, Roberto; Velazquez-Angulo, Gilberto; Flores-Tavizón, Edith; Romero-González, Jaime; Huertas-Cardozo, José Ignacio

    2016-01-01

    This study examines a pathway for building urban climate change mitigation policies by presenting a multi-dimensional and transdisciplinary approach in which technical, economic, environmental, social, and political dimensions interact. Now, more than ever, the gap between science and policymaking needs to be bridged; this will enable judicious choices to be made in regarding energy and climate change mitigation strategies, leading to positive social impacts, in particular for the populations at-risk at the local level. Through a case study in Juarez, Chihuahua, Mexico, we propose a multidimensional and transdisciplinary approach with the role of scientist as policy advisers to improve the role of science in decision-making on mitigation policies at the local level in Mexico. PMID:27128933

  10. The Role of Science in Advising the Decision Making Process: A Pathway for Building Effective Climate Change Mitigation Policies in Mexico at the Local Level

    Directory of Open Access Journals (Sweden)

    Roberto Barraza

    2016-04-01

    Full Text Available This study examines a pathway for building urban climate change mitigation policies by presenting a multi-dimensional and transdisciplinary approach in which technical, economic, environmental, social, and political dimensions interact. Now, more than ever, the gap between science and policymaking needs to be bridged; this will enable judicious choices to be made in regarding energy and climate change mitigation strategies, leading to positive social impacts, in particular for the populations at-risk at the local level. Through a case study in Juarez, Chihuahua, Mexico, we propose a multidimensional and transdisciplinary approach with the role of scientist as policy advisers to improve the role of science in decision-making on mitigation policies at the local level in Mexico.

  11. The Role of Science in Advising the Decision Making Process: A Pathway for Building Effective Climate Change Mitigation Policies in Mexico at the Local Level

    Science.gov (United States)

    Barraza, Roberto; Velazquez-Angulo, Gilberto; Flores-Tavizón, Edith; Romero-González, Jaime; Huertas-Cardozo, José Ignacio

    2016-01-01

    This study examines a pathway for building urban climate change mitigation policies by presenting a multi-dimensional and transdisciplinary approach in which technical, economic, environmental, social, and political dimensions interact. Now, more than ever, the gap between science and policymaking needs to be bridged; this will enable judicious choices to be made in regarding energy and climate change mitigation strategies, leading to positive social impacts, in particular for the populations at-risk at the local level. Through a case study in Juarez, Chihuahua, Mexico, we propose a multidimensional and transdisciplinary approach with the role of scientist as policy advisers to improve the role of science in decision-making on mitigation policies at the local level in Mexico. PMID:27128933

  12. Terrestrial Spaceflight Analogs: Antarctica

    Science.gov (United States)

    Crucian, Brian

    2013-01-01

    Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

  13. USW area analogs

    OpenAIRE

    Everett, Keith R.

    2005-01-01

    The purpose of this project is to investigate the feasibility of and methodology for the development of a set of environmental analogs of operational Undersea Warfare (USW) areas within fleet training areas. It is primarily a discussion of the identification of parameters that characterize the tactical USW environment, prioritization of these parameters, identification of existing databases that contain these parameters and an outline of the processes required to extract the desired data fro...

  14. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John eHummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  15. ADSL Analog Front End

    OpenAIRE

    Stojković, Nino

    2006-01-01

    In this paper the Asymmetric Digital Subscriber Line (ADSL) analog front end (AFE) designs are described and compared. AFE is the part of ADSL modems most responsible for quality signal transmission over phone wires. It can be divided into the transmitting path (TX) circuitry, the receiving path (RX) circuitry and the hybrid network and transformer. The operations and realizations of each functional block are presented. There are the D/A converter, the filter and the line driver in the TX pat...

  16. Analog Signal Processing

    OpenAIRE

    Caloz, Christophe; Gupta, Shulabh; Zhang, Qingfeng; Nikfal, Babak

    2013-01-01

    Analog signal processing (ASP) is presented as a systematic approach to address future challenges in high speed and high frequency microwave applications. The general concept of ASP is explained with the help of examples emphasizing basic ASP effects, such as time spreading and compression, chirping and frequency discrimination. Phasers, which represent the core of ASP systems, are explained to be elements exhibiting a frequency-dependent group delay response, and hence a nonlinear phase resp...

  17. A Transiting Jupiter Analog

    CERN Document Server

    Kipping, David M; Henze, Chris; Teachey, Alex; Isaacson, Howard T; Petigura, Erik A; Marcy, Geoffrey W; Buchhave, Lars A; Chen, Jingjing; Bryson, Steve T; Sandford, Emily

    2016-01-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of $(0.91\\pm0.02)$ $R_{\\mathrm{Jup}}$, a low orbital eccentricity ($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\\pm3)$ K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric ...

  18. Spiral structure in galaxies: analogies

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, R.C.

    1976-01-01

    The vortex analogy to galactic spiral structures is considered. Caution against carrying the analogy past its region of applicability is noted; and some experiments with vorticities are mentioned. (JFP)

  19. La violencia en la región noroeste de Chihuahua. Experiencias e impactos desde la comunidad educativa

    Directory of Open Access Journals (Sweden)

    Marcos J. Estrada Ruiz

    2013-01-01

    Full Text Available La violencia escolar ha sido un tema explorado de manera importante en los últimos años desde la investigación educativa en México, sin embargo, en contextos de alta violencia no se han mostrado los impactos de la violencia extraescolar y estructural, en la escuela y en otros espacios comunitarios. El artículo presenta resultados de una investigación que tuvo por objetivo reconstruir el impacto de la violencia en la región noroeste de Chihuahua, desde la comunidad educativa (docentes, padres, estudiantes de dos municipios en particular. A la manera de estudios en caso y recurriendo al análisis de contenido, se analizanlos impactos en la percepción del incremento de la violencia a partir de la experiencia directa; la modificación de la dinámica de las escuelas; el abandono de los espacios públicos y el señalamiento de “nuevos” actores, aparentemente ajenos a la comunidad, que aparecen a priori por su condición social, como los responsables de la violencia.

  20. Baccharis Salicifolia development in the presence of high concentrations of uranium in the arid environment of San Marcos, Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Luna P, M. Y.; Alarcon H, M. T.; Silva S, M.; Renteria V, M; Rodriguez V, M. A.; Herrera P, E.; Reyes C, M.; Montero C, M. E., E-mail: elena.montero@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico)

    2011-02-15

    In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. The results indicate a tendency for the plant to accumulate the uranium in its different parts, and to trans locate it to its stem and leaves. The plant is resistant to high concentrations of uranium, not showing any specific changes in relation to non contaminated areas that might indicate the presence of the contaminant. Therefore, its use as a bio monitor species is limited. (Author)

  1. Baccharis Salicifolia development in the presence of high concentrations of uranium in the arid environment of San Marcos, Chihuahua

    International Nuclear Information System (INIS)

    In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. The results indicate a tendency for the plant to accumulate the uranium in its different parts, and to trans locate it to its stem and leaves. The plant is resistant to high concentrations of uranium, not showing any specific changes in relation to non contaminated areas that might indicate the presence of the contaminant. Therefore, its use as a bio monitor species is limited. (Author)

  2. The Age of Analog Networks

    OpenAIRE

    Mattiussi, Claudio; Swiss Federal Institute of Technology in Lausanne (EPFL); Marbach, Daniel; Swiss Federal Institute of Technology in Lausanne (EPFL); Dürr, Peter; Swiss Federal Institute of Technology in Lausanne (EPFL); Floreano, Dario; Swiss Federal Institute of Technology in Lausanne (EPFL)

    2008-01-01

    A large class of systems of biological and technological relevance can be described as analog networks, that is, collections of dynamical devices interconnected by links of varying strength. Some examples of analog networks are genetic regulatory networks, metabolic networks, neural networks, analog electronic circuits, and control systems. Analog networks are typically complex systems which include nonlinear feedback loops and possess temporal dynamics at different timescales. When tackled b...

  3. Glucose-6-phosphate dehydrogenase deficiency in northern Mexico and description of a novel mutation

    Indian Academy of Sciences (India)

    N. García-Magallanes; F. Luque-Ortega; E. M. Aguilar-Medina; R. Ramos-Payán; C. Galaviz-Hernández; J. G. Romero-Quintana; L. Del Pozo-Yauner; H. Rangel-Villalobos; E. Arámbula-Meraz

    2014-08-01

    Glucose-6-phosphate dehydrogenase deficiency (G6PD) is the most common enzyme pathology in humans; it is X-linked inherited and causes neonatal hyperbilirubinaemia, chronic nonspherocytic haemolytic anaemia and drug-induced acute haemolytic anaemia. G6PD deficiency has scarcely been studied in the northern region of Mexico, which is important because of the genetic heterogeneity described in Mexican population. Therefore, samples from the northern Mexico were biochemically screened for G6PD deficiency, and PCR-RFLPs, and DNA sequencing used to identify mutations in positive samples. The frequency of G6PD deficiency in the population was 0.95% ($n = 1993$); the mutations in 86% of these samples were G6PD A-202A/376G, G6PD A-376G/968C and G6PD Santamaria376G/542T. Contrary to previous reports, we demonstrated that G6PD deficiency distribution is relatively homogenous throughout the country $(P = 0.48336)$, and the unique exception with high frequency of G6PD deficiency does not involve a coastal population (Chihuahua: 2.4%). Analysis of eight polymorphic sites showed only 10 haplotypes. In one individual we identified a new G6PD mutation named Mexico DF193A>G (rs199474830), which probably results in a damaging functional effect, according to PolyPhen analysis. Proteomic impact of the mutation is also described.

  4. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  5. Discrete Calculus by Analogy

    CERN Document Server

    Izadi, F A; Bagirov, G

    2009-01-01

    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  6. An analog electronic cochlea

    OpenAIRE

    Lyon, Richard F.; Mead, Carver

    1988-01-01

    An engineered system that hears, such as a speech recognizer, can be designed by modeling the cochlea, or inner ear, and higher levels of the auditory nervous system. To be useful in such a system, a model of the cochlea should incorporate a variety of known effects, such as an asymmetric low-pass/bandpass response at each output channel, a short ringing time, and active adaptation to a wide range of input signal levels. An analog electronic cochlea has been built in CMOS VLSI technolog...

  7. Medición de la vulnerabilidad: el caso de la adicción a drogas ilícitas en Chihuahua, México

    OpenAIRE

    Roberto J. Córdova-Contreras; Idrovo, Álvaro J.

    2010-01-01

    En el presente estudio se explora el modelo de Rogers para cuantificar la vulnerabilidad, pero sin pruebas empíricas de su utilidad. Éste usa un triángulo equilátero cuyos lados representan los recursos personales y el apoyo ambiental, y la base el grado de vulnerabilidad. Se comparan los datos de la Encuesta estatal de adicciones del estado de Chihuahua, del año 2000, con los resultados obtenidos con la visión tradicional de la epidemiología. El enfoque de la vulnerabilidad identificó a la p...

  8. Análisis de la cobertura visual de las torres de detección de incendios forestales, en Chihuahua México

    OpenAIRE

    M. Pompa-García; E. Treviño-Garza

    2004-01-01

    En este trabajo se presenta un análisis de la cobertura de visibilidad de las torres de detección de incendios forestales en el estado de Chihuahua. Para este proceso se recolectó información geográfica en campo de 32 torres usando el sistema mapa móvil. Después de digitalizar esta información, fue integrada sobre el modelo digital de elevación y la cartografía del inventario forestal nacional del año 2000, generándose las coberturas correspondientes. El resultado de este proceso es ...

  9. Criminalidad, inseguridad pública y comportamiento de los electores: un análisis del proceso electoral estatal 2010 en Ciudad Juárez, Chihuahua

    OpenAIRE

    Andrés Valdez Zepeda; Abraham Paniagua Vázquez

    2011-01-01

    En este escrito se hace un análisis del efecto de la crisis de inseguridad pública derivada de la llamada guerra contra el narcotráfico en la conducta del votante en un momento electoral, a la luz de las diferentes teorías sobre el voto. Se describe en lo particular el efecto de la actual crisis de inseguridad pública en los resultados de las elecciones locales del 2010 en Ciudad Juárez, Chihuahua, México. Se concluye que una crisis de inseguridad y violencia orienta el comportamiento elect...

  10. Elaboración del duelo de una madre cuyo hijo trabajaba como sicario en Ciudad Juárez, Chihuahua

    OpenAIRE

    Rosalía Delgado Durán

    2014-01-01

    El presente trabajo es parte de una investigación cualitativa sobre el proceso de ela - boración de duelo de la madre de un sicario en el contexto de una terapia Gestalt. Se utilizó para su análisis la perspectiva de las etapas del duelo de Kübler-Ross (2006:59- 119). La exacerbación de la violencia generada en buena medida por pugnas entre gru - pos del crimen organizado en Ciudad Juárez, Chihuahua (Martínez, 2008), ha dado como resultado una gran cantidad de muertes, una de ellas es el caso...

  11. Empleo, escolaridad y sector informal en la Frontera Norte de México y Chihuahua: expectativas de ocupación en la crisis.

    OpenAIRE

    Luis Huesca Reynoso; Martha Beatriz Padilla Arriola

    2012-01-01

    El trabajo muestra un análisis de la distribución de los ingresos y las expectativas de ocupación para dos grupos de trabajadores, uno en la Frontera Norte de México y otro en Chihuahua, durante el año de la crisis de 2009 hasta 2011. El objetivo es determinar si las oportunidades de obtener un trabajo formal en esta región mejoran los ingresos de sus trabajadores que se desempeñan como informales. Se observa una mayor participación del trabajo informal por cuenta propia y los asalariados, co...

  12. Effect of the temperature on the sorption of cadmium in natural clinoptilolite from the State of Chihuahua; Efecto de la temperatura sobre la sorcion de cadmio en clinoptilolita natural del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Arambula V, V

    2004-07-01

    The investigation works related with the removal of cadmium of aqueous solutions, they make emphasis in a great number of materials that were used for this end, as well as in the parameters that influence, such as the temperature and the pH. In this work it was investigated the effect of the temperature on the removal of cadmium, using a zeolitic mineral native of the State of Chihuahua for they were determined it kinetic parameters, those diffusivity coefficients and the retention mechanisms (adsorption or ion exchange) involved. The clinoptilolite samples were characterized by means of scanning electron microscopy in high vacuum (MEB), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part consisted on putting in contact solutions of cadmium with the mineral, varying the temperature, the time of contact or the concentration; the quantification of sodium and cadmium in the liquid phase was carried out by means of atomic absorption spectroscopy (EAA). It was determined the time of equilibrium for the removal process. The temperature and the concentration influence on the process of sorption of cadmium in the zeolitic mineral (kinetics and isotherms). The kinetic model that describes better the sorption process of cadmium in the clinoptilolite was the pseudo-2 order. The apparent coefficient of diffusivity presented a greater value conforms to increment the temperature. The results of the isotherm of adsorption of cadmium presented a better adjustment to the Freundlich model. The quantity of cadmium retained by the mineral it was greater than the quantity of sodium found in the solution after the contact between the solution of cadmium and the zeolitic mineral and in accordance with the obtained separation factors, the natural zeolite shows a greater affinity for the cadmium that for the sodium ({alpha} > 1). (Author)

  13. Mexico: prospects for democracy

    OpenAIRE

    Norton, Yvonne D.

    1996-01-01

    The purpose of this thesis is to analyze why Mexico has failed to democratize and offer recommendations for U.S. policy towards Mexico. The thesis examines the impact of three casual variables on the level of democracy in Mexico: civilian control of the military, the fairness of Mexico's political party system, and U.S. foreign policy towards Mexico. NA U.S. Navy (U.S.N.) author

  14. Gestión de conocimiento en PyME del sector servicios en la ciudad de Chihuahua

    Directory of Open Access Journals (Sweden)

    María del Carmen Gutiérrez-Diez

    2015-01-01

    Full Text Available La gestión de conocimiento es fundamental en la sobrevivencia de las PyME. Este trabajo describe los resultados, obtenidos hasta mayo del 2013, donde en particular se estudian los procesos de gestión de conocimiento, en treinta PyME del sector de servicios, ubicadas en la ciudad de Chihuahua. Se usó como marco de referencia el modelo de espiral de creación de conocimiento organizacional de Nonaka y Takeuchi., a partir del cual de evaluaron las dimensiones de Socialización, Interiorización, Exteriorización y Combinación. Se desarrolló y aplicó un instrumento, dirigido a los empleadores. Los resultados fueron analizados a través de una estadistica descriptiva, correlacional y regresión lineal. En los resultados obtenidos, se describen los valores asignados por los empleadores a estas diferentes categorías. Se obtuvo que las categorías de Socialización y Combinación muestran aportaciones más bajas, mientras que Exteriorización, Interiorización y Combinación aportan más al proceso de gestión de conocimiento. Lo anterior permite concluir una clara falta de estrategias y procesos que favorezcan la generación del conocimiento organizacional para estas PyME, en particular en las actividades de Socialización y Combinación.

  15. Effect of the temperature on the sorption of cadmium in natural clinoptilolite from the State of Chihuahua

    International Nuclear Information System (INIS)

    The investigation works related with the removal of cadmium of aqueous solutions, they make emphasis in a great number of materials that were used for this end, as well as in the parameters that influence, such as the temperature and the pH. In this work it was investigated the effect of the temperature on the removal of cadmium, using a zeolitic mineral native of the State of Chihuahua for they were determined it kinetic parameters, those diffusivity coefficients and the retention mechanisms (adsorption or ion exchange) involved. The clinoptilolite samples were characterized by means of scanning electron microscopy in high vacuum (MEB), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part consisted on putting in contact solutions of cadmium with the mineral, varying the temperature, the time of contact or the concentration; the quantification of sodium and cadmium in the liquid phase was carried out by means of atomic absorption spectroscopy (EAA). It was determined the time of equilibrium for the removal process. The temperature and the concentration influence on the process of sorption of cadmium in the zeolitic mineral (kinetics and isotherms). The kinetic model that describes better the sorption process of cadmium in the clinoptilolite was the pseudo-2 order. The apparent coefficient of diffusivity presented a greater value conforms to increment the temperature. The results of the isotherm of adsorption of cadmium presented a better adjustment to the Freundlich model. The quantity of cadmium retained by the mineral it was greater than the quantity of sodium found in the solution after the contact between the solution of cadmium and the zeolitic mineral and in accordance with the obtained separation factors, the natural zeolite shows a greater affinity for the cadmium that for the sodium (α > 1). (Author)

  16. Vorticity in analog gravity

    Science.gov (United States)

    Cropp, Bethan; Liberati, Stefano; Turcati, Rodrigo

    2016-06-01

    In the analog gravity framework, the acoustic disturbances in a moving fluid can be described by an equation of motion identical to a relativistic scalar massless field propagating in curved space-time. This description is possible only when the fluid under consideration is barotropic, inviscid, and irrotational. In this case, the propagation of the perturbations is governed by an acoustic metric that depends algebrically on the local speed of sound, density, and the background flow velocity, the latter assumed to be vorticity-free. In this work we provide a straightforward extension in order to go beyond the irrotational constraint. Using a charged—relativistic and nonrelativistic—Bose–Einstein condensate as a physical system, we show that in the low-momentum limit and performing the eikonal approximation we can derive a d’Alembertian equation of motion for the charged phonons where the emergent acoustic metric depends on flow velocity in the presence of vorticity.

  17. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  18. Millennial-scale records of North American Monsoon in time and space during the last glacial period: reconstructions from arid northern Mexico

    Science.gov (United States)

    Roy, P.; Quiroz-Jiménez, D.; Charles-Polo, M.; Lozano-Santacruz, R.

    2013-05-01

    The arid northern Mexico is part of the Sonora and Chihuahua Deserts and both the deserts belong to the North American Desert system. The North American Monsoon (NAM) or Mexican Monsoon refers to the system that brings summer precipitation to arid northern Mexico and southwestern USA. It contributes ca. 70-80% of total annual precipitation along the western slopes of the Sierra Madre Occidental (northern Mexico) and ca. 40-50% of total precipitation in Arizona and New Mexico (southwest USA). High-resolution geochemical data from lacustrine deposits located between 23°N and 31°N (paleolakes La Salada, Babicora and San Felipe) provide spatio-temporal and millennial-scale paleohydrological records related to the dynamics of summer precipitation as well as westerly winter storms over the last glacial period. The inverse relationship between proxy records of runoff into lacustrine basins of northern Mexico and winter precipitation over the southwestern USA indicate that the westerly winter storms had minimal influence south of 30°N and the paleohydrological changes are mainly summer precipitation controlled. The variation in summer season precipitation between 20 and 60 cal. kyr BP was driven by long term changes in summer insolation. During an interval of lower summer insolation (i.e. >60 cal. kyr BP), the higher summer precipitation could be related to the NAM expansion as a result of reduced north hemisphere ice sheets. On a millennial-scale, the region received more than average precipitation during the warm interstadials and vice versa.

  19. Analogy-Based Expectation Equilibrium

    OpenAIRE

    Jehiel, P

    2001-01-01

    It is assumed that players bundle nodes in which other players must move into analogy classes, and players only have expectations about the average behavior in every class. A solution concept is proposed for multi-stage games with perfect information: at every node players choose best-responses to their analogy-based expectations, and expectations are correct on average over those various nodes pooled together into the same analogy classes. The approach is applied to a variety of games. It is...

  20. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  1. Analog and digital signal processing

    Science.gov (United States)

    Baher, H.

    The techniques of signal processing in both the analog and digital domains are addressed in a fashion suitable for undergraduate courses in modern electrical engineering. The topics considered include: spectral analysis of continuous and discrete signals, analysis of continuous and discrete systems and networks using transform methods, design of analog and digital filters, digitization of analog signals, power spectrum estimation of stochastic signals, FFT algorithms, finite word-length effects in digital signal processes, linear estimation, and adaptive filtering.

  2. Correlation of the activity of the 238 U in soil and 222 Rn in domiciles, with the rocks of cities of the Estado de Chihuahua

    International Nuclear Information System (INIS)

    The state of Chihuahua has numerous locations of uranium, being Pena Blanca the great and more important location of the country. Diverse rock types with important quantities of uranium are distributed by the whole state. The igneous extrusive acid rocks are those that have bigger quantity of uranium, like they are the rhyolites and dacites and these rocks are located in enough proportion by the whole state. Some of the main cities of the state are near to locations or uraniferous rocks, as Aldama, Nuevo Casas Grandes, Chihuahua, Jimenez and Bocoyna, other important cities are not near important locations. It was determined specific activity by gamma spectroscopy of the series of the 238 U in soils and determination of the radon concentration in domiciles of the main cities of the state. They were found high specific activity values in soil in eight of the thirteen analyzed cities and important radon concentrations in three cities. It was found relationship among the specific activity in soil in near cities to uraniferous locations. (Author)

  3. Isolated transfer of analog signals

    Science.gov (United States)

    Bezdek, T.

    1974-01-01

    Technique transfers analog signal levels across high isolation boundary without circuit performance being affected by magnetizing reactance or leakage inductance. Transfers of analog information across isolated boundary are made by interrupting signal flow, with switch, in such a manner as to produce alternating signal which is applied to transformer.

  4. Drawing Analogies in Environmental Education

    Science.gov (United States)

    Affifi, Ramsey

    2014-01-01

    Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

  5. Analog elements for transuranic chemistries

    International Nuclear Information System (INIS)

    A chemical extraction technique for estimating the biologically available fraction of nonessential trace elements in soils has been developed. This procedure has been used in evaluating the uptake of naturally occurring transuranic analog elements from soils into several foodstuffs. The availability of the natural elements has been compared with the availability of their analog transuranics which have been derived from global fallout

  6. Natural analog studies: Licensing perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, J.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This report describes the licensing perspective of the term {open_quotes}natural analog studies{close_quotes} as used in CFR Part 60. It describes the misunderstandings related to its definition which has become evident during discussions at the U.S Nuclear Regulatory Commission meetings and tries to clarify the appropriate applications of natural analog studies to aspects of repository site characterization.

  7. New Mexico National Cemeteries

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The United States Department of Veterans Affairs National Cemetery Administration maintains 2 national cemeteries in the state of New Mexico; the Fort Bayard...

  8. New Mexico Golf Courses

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of golf courses in New Mexico, in point form, with limited attributes, compiled using available data from...

  9. New Mexico Parks

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of parks in New Mexico, in point form, with limited attributes, compiled using available data from a...

  10. New Mexico Convention Centers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of convention centers in New Mexico, in point form, with limited attributes, compiled using available data...

  11. New Mexico Ghost Towns

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data provides locations and non-spatial attributes of many ghost towns in the State of New Mexico, compiled from various sources. Locations provided with...

  12. New Mexico State Parks

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the generalized physical boundaries of New Mexico State Parks, in polygonal form with limited attributes, compiled using...

  13. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2009-01-01

    This Selected Issues paper on Mexico presents econometric investigation of the cyclical determinants of remittances to Mexico. The aggregate U.S. business cycle is not necessarily relevant for remittances. Remittances to Mexico do show a significant relationship with employment conditions in certain regions of the United States. Employment conditions in the U.S. construction sector seem to be especially important as well as remittances for certain regions of Mexico with high rates of emigrati...

  14. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2006-01-01

    This Selected Issues paper is a wide-ranging survey of the conditions for, and obstacles to, the growth in Mexico. It frames the issue of Mexico’s growth record, and presents the paper’s prior assumptions and approach. It highlights the main observations and conclusions emerging from the survey of growth conditions in Mexico. It also presents an overview of remittances in Mexico, motivated by their recent increase and possible macroeconomic implications.

  15. Caracterización morfológica y molecular de Leptochloa dubia (Poaceae en Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Carlos Morales-Nieto

    2015-08-01

    Full Text Available El gigante [Leptochloa dubia(Kunth Nees.] es una importante gramínea forrajera nativa de México, cuyas poblaciones naturales se han reducido debido a malas prácticas de pastoreo. En este trabajo se analizó la variabilidad morfológica y genética de 32 poblaciones del gigante en el estado de Chihuahua, México. Nueve características morfológicas fueron evaluadas en estas poblaciones, después de dos años de trasplantadas y establecidos en un jardín de observación y bajo condiciones de temporal. La variabilidad genética se determinó utilizando los perfiles de amplificación de cuatro pares de iniciadores u oligonucleótidos. El análisis de componentes principales mostró que los tres primeros componentes explicaron el 75.3% de la variación morfológica. Los cuatro pares de iniciadores produjeron un total de 186 bandas, de las cuales el 56.45% presentó polimorfismo. La combinación de iniciadores EcoRI-AAC+MseI-CAG detectó el mayor porcentaje de polimorfismo (69.57% y 32 bandas polimórficas. El coeficiente de Dice y análisis de agrupamiento generaron cinco grupos. La variabilidad genética y morfológica encontrada en las diferentes poblaciones, podrían servir de base para la selección de ecotipos de gigante para diversos propósitos como producción de semilla, retención de suelo, restauración de ecosistemas y forraje para libre pastoreo o de corte, entre otros. Así también, los resultados de este trabajo son la base para iniciar programas de mejoramiento genético en esta especie.

  16. Psychology in Mexico

    Science.gov (United States)

    Ruiz, Eleonora Rubio

    2011-01-01

    The first formal psychology course taught in Mexico was in 1896 at Mexico's National University; today, National Autonomous University of Mexico (UNAM in Spanish). The modern psychology from Europe and the US in the late 19th century were the primary influences of Mexican psychology, as well as psychoanalysis and both clinical and experimental…

  17. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  18. Estimating maquiladora hazardous waste generation on the U.S./Mexico border

    Science.gov (United States)

    Bowen, Mace M.; Kontuly, Thomas; Hepner, George F.

    1995-03-01

    Maquiladoras, manufacturing plants that primarily assemble foreign components for reexport, are located in concentrations along the northern frontier of the US/Mexico border. These plants process a wide variety of materials using modern industrial technologies within the context of developing world institutions and infrastructure. Hazardous waste generation by maquiladoras represents a critical environmental management issue because of the spatial concentration of these plants in border municipalities where the infrastructure for waste management is nonexistent or poor. These border municipalities contain rapidly increasing populations, which further stress their waste handling infrastructure capacities while exposing their populations to greater contaminant risks. Limited empirical knowledge exists concerning hazardous waste types and generation rates from maquiladorsas. There is no standard reporting method for waste generation or methodology for estimating generation rates at this time. This paper presents a method that can be used for the rapid assessment of hazardous waste generation. A first approximation of hazardous waste generation is produced for maquiladoras in the three municipalities of Nogales, Sonora, Mexicali, Baja California, and Cd. Juarez, Chihuahua, using the INVENT model developed by the World Bank. In addition, our intent is to evaluate the potential of the INVENT model for adaptation to the US/Mexico border industrial situation. The press of border industrial development, especially with the recent adoption of the NAFTA, make such assessments necessary as a basis for the environmental policy formulation and management needed in the immediate future.

  19. Molecular modeling of fentanyl analogs

    Directory of Open Access Journals (Sweden)

    LJILJANA DOSEN-MICOVIC

    2004-11-01

    Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

  20. Analog Systems for Gravity Duals

    OpenAIRE

    Hossenfelder, S.

    2014-01-01

    We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog gravity therefore ...

  1. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  2. Towards power centric analog design

    OpenAIRE

    Svensson, Christer

    2015-01-01

    Power consumption of analog systems is poorly understoodtoday, in contrast to the very well developed analysis of digitalpower consumption. We show that there is good opportunity todevelop also the analog power understanding to a similar levelas the digital. Such an understanding will have a large impact inthe design of future electronic systems, where low power consumptionwill be crucial. Eventually we may reach a power centricanalog design methodology.

  3. Prevalencia de desnutrición en niños tarahumaras menores de cinco años en el municipio de Guachochi, Chihuahua

    OpenAIRE

    Monárrez Joel; Martínez Homero

    2000-01-01

    OBJETIVO: Determinar la prevalencia de desnutrición en niños tarahumaras menores de cinco años en el municipio de Guachochi, Chihuahua, México. MATERIAL Y MÉTODOS: Durante el verano de 1996, fueron muestreados 450 niños, representativos de 62 comunidades, estratificadas por el tamaño de su población. La muestra representa 12.2% del total de tarahumaras del municipio. Para cada uno de los índices antropométricos peso/edad, peso/talla y talla/edad se calculó la desviación en puntaje Z de cada o...

  4. Un acercamiento al concepto de representación: el caso de las mujeres políticas en el estado de Chihuahua

    Directory of Open Access Journals (Sweden)

    Martha Estela Pérez

    2013-01-01

    Full Text Available En este documento se reflexiona sobre el fenómeno de la representación simbólica y política de las mujeres en el estado de Chihuahua. Este caso se centra en la escasa representación del sexo femenino en la política institucional y, de igual forma, se hace un acercamiento a los esquemas culturales que siguen vigentes en la esfera pública, los cuales no sólo inciden en el quehacer político femenino y masculino, sino que también conllevan a generar espacios de discriminación e inequidad y obstaculizan el empoderamiento femenino.

  5. Contextualización reticular de la Responsabilidad Social Empresarial global y el desarrollo bioregional en Ciudad Juárez, Chihuahua-El Paso, Texas

    Directory of Open Access Journals (Sweden)

    María Luisa Picard-Ami Vogan

    2012-01-01

    Full Text Available The study proposes to approach the phenomenon by providing a networking context to Corporate Social Responsibility, the influences it receives from globalization, and the way it influences the bioregional borderland development of Ciudad Juarez and El Paso. The lens of social responsibility serves to examine a return to the private and social contextualization which occurs when an enterprise proactively uses its capacity to invest its resources on the benefit of society. In doing so, it contributes to creating an environment for investment and sustainable socioeconomic and sociopo litical growth by tapping into the support of different stakeholders and by capitalizing on transnational and personal and institutional networks. This study will use social network analysis to analyze the civic, corporate and governmental sectors in Ciudad Juarez, Chihuahua, and El Paso, Texas, and the proposed actions in the past decade to promote bioregional economic development.

  6. Medición de la vulnerabilidad: el caso de la adicción a drogas ilícitas en Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Roberto J. Córdova-Contreras

    2010-01-01

    Full Text Available En el presente estudio se explora el modelo de Rogers para cuantificar la vulnerabilidad, pero sin pruebas empíricas de su utilidad. Éste usa un triángulo equilátero cuyos lados representan los recursos personales y el apoyo ambiental, y la base el grado de vulnerabilidad. Se comparan los datos de la Encuesta estatal de adicciones del estado de Chihuahua, del año 2000, con los resultados obtenidos con la visión tradicional de la epidemiología. El enfoque de la vulnerabilidad identificó a la población analizada como muy sensible. La comparación entre los métodos mostró diferencias importantes, pero no permiten inferir cuál es mejor. Estudios futuros podrán examinar la utilidad del modelo abordado aquí, en diversos contextos.

  7. Natural CO2 Analogs for Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott H. Stevens; B. Scott Tye

    2005-07-31

    The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic formations. Geologic, engineering, and operational databases were developed for McElmo Dome in Colorado; St. Johns Dome in Arizona and New Mexico; and Jackson Dome in Mississippi. The three study sites stored a total of 2.4 billion t (46 Tcf) of CO{sub 2} equivalent to 1.5 years of power plant emissions in the US and comparable in size with the largest proposed sequestration projects. The three CO{sub 2} fields offer a scientifically useful range of contrasting geologic settings (carbonate vs. sandstone reservoir; supercritical vs. free gas state; normally pressured vs. overpressured), as well as different stages of commercial development (mostly undeveloped to mature). The current study relied mainly on existing data provided by the CO{sub 2} field operator partners, augmented with new geochemical data. Additional study at these unique natural CO{sub 2} accumulations could further help guide the development of safe and cost-effective design and operation methods for engineered CO{sub 2} storage sites.

  8. Correlation of the activity of the {sup 238} U in soil and {sup 222} Rn in domiciles, with the rocks of cities of the Estado de Chihuahua; Correlacion de la actividad del {sup 238} U en suelo y {sup 222} Rn en domicilios, con las rocas de ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.; Villalba, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes 120 C.P. 31109 Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2004-07-01

    The state of Chihuahua has numerous locations of uranium, being Pena Blanca the great and more important location of the country. Diverse rock types with important quantities of uranium are distributed by the whole state. The igneous extrusive acid rocks are those that have bigger quantity of uranium, like they are the rhyolites and dacites and these rocks are located in enough proportion by the whole state. Some of the main cities of the state are near to locations or uraniferous rocks, as Aldama, Nuevo Casas Grandes, Chihuahua, Jimenez and Bocoyna, other important cities are not near important locations. It was determined specific activity by gamma spectroscopy of the series of the {sup 238} U in soils and determination of the radon concentration in domiciles of the main cities of the state. They were found high specific activity values in soil in eight of the thirteen analyzed cities and important radon concentrations in three cities. It was found relationship among the specific activity in soil in near cities to uraniferous locations. (Author)

  9. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. PMID:25532894

  10. Organic beekeeping in Mexico

    OpenAIRE

    Garibay, Salvador V.; Vandame, Rémy

    2011-01-01

    Mexico is often described as a cornucopia, a land with high diversity in ecosystems, crops, fauna and flora. These are superb preconditions for organic honey production. Already the pre-hispanic Maya cultures produced honey from the native stingless bee (Meliponini) before the Spanish introduced European honey bee (Apis mellifera L). The main beekeeping product in Mexico is honey. Mexico ranks sixth in the world in honey production (57,000 t) and third as an exporter (25,000 t).

  11. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2005-01-01

    This Selected Issues paper considers the “informal sector†in Mexico. In Mexico and many other countries, the informal sector represents a large share of total employment. The paper reviews the literature on informality, with special focus on findings for Mexico, and develops a theoretical model that highlights the importance of externalities and the distortion associated with the informal sector. The analysis provides insight into the kinds of policy measures that might sustainably reduce...

  12. Organic Beekeeping in Mexico

    OpenAIRE

    Garibay, Salvador; Gänz, Peter; Vandame, Rémy

    2010-01-01

    Mexico is often described as a cornucopia, a land with high diversity in ecosystems, crops, fauna and flora. These are superb preconditions for organic honey production. Already the pre-hispanic Maya cultures produced honey from the native stingless bee (Meliponini) before the Spanish introduced European honey bee (Apis mellifera L). The main beekeeping product in Mexico is honey. Mexico ranks sixth in the world in honey production (57,000 t) and third as an exporter (25,000 t). Two condit...

  13. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  14. Competition Policy in Mexico

    OpenAIRE

    Ernesto Estrada Gonzalez

    2008-01-01

    The CFC faces significant challenges from cartel activity, prevailing regulatory restrictions on competition, and exclusionary practices undertaken by some of the most powerful corporations in Mexico.

  15. Multilateral Collaborations in Analog Research

    Science.gov (United States)

    Cromwell, R. l.

    2016-01-01

    International collaborations in studies utilizing ground-based space flight analogs are an effective means for answering research questions common to participating agencies. These collaborations bring together worldwide experts to solve important space research questions. By collaborating unnecessary duplication of science is reduced, and the efficiency of analog use is improved. These studies also share resources among agencies for cost effective solutions to study implementation. Recently, NASA has engaged in collaborations with international partners at a variety of analog sites. The NASA Human Exploration Research Analog (HERA) is currently hosting investigator studies from NASA and from the German Space Agency (DLR). These isolation studies will answer questions in the areas of team cohesion, sleep and circadian rhythms, and neurobehavioral correlates to function. Planning for the next HERA campaign is underway as proposal selections are being made from the International Life Sciences Research Announcement (ILSRA). Studies selected from the ILSRA will be conducted across 4 HERA missions in 2017. NASA is planning collaborative studies with DLR at the :envihab facility in Cologne, Germany. Investigations were recently selected to study the effects of 0.5% CO2 exposure over 30 days of bed rest. These studies will help to determine the fidelity of this ground-based analog for studying the visual impairment intracranial pressure syndrome. NASA is also planning a multilateral collaboration at :envihab with DLR and the European Space Agency (ESA) to examine artificial gravity as a countermeasure to mitigate the effects of 60 days of bed rest. NASA is also considering collaborations with the Russian Institute for Biomedical Problems (IBMP) in studies that will utilize their Ground-based Experimental Facility (NEK). The NEK is comprised of 4 interconnected modules and a Martian surface simulator. This isolation analog can support 3 -10 crew members for long duration

  16. Application handbook for analog IC

    International Nuclear Information System (INIS)

    This book consists of ten chapters, which are prolog on analog IC and digital, basic function of OP amp for operation, characteristic on direct current and interchange, Op amp and linear circuit, nonlinear arithmetic circuit, filter circuit, oscillation circuit and V-F converter, D-A converter, A-D converter on introduction eight bit and 12 bit, I C for power supply and switching regulator. Each chapter has the explanations of specific function of the programs, filter circuit, converters. So, this book is a application handbook for analog IC.

  17. International Alligator Rivers Analog Project

    International Nuclear Information System (INIS)

    The Australian Nuclear Science and Technology Organization (ANSTO), the Japan Atomic Energy Research Institute, the Swedish Nuclear Power Inspectorate, the U.K. Department of the Environment, the US Nuclear Regulatory Commission (NRC), and the Power Reactor and Nuclear Fuel Development Corporation of Japan are participating under the aegis of the Nuclear Energy Agency in the International Alligator Rivers Analog Project. The project has a duration of 3 yr, starting in 1988. The project has grown out of a research program on uranium ore bodies as analogs of high-level waste (HLW) repositories undertaken by ANSTO supported by the NRC. A primary objective of the project is to develop an approach to radionuclide transport model validation that may be used by the participants to support assessments of the safety of radioactive waste repositories. The approach involves integrating mathematical and physical modeling with hydrological and geochemical field and laboratory investigations of the analog site. The Koongarra uranium ore body has been chosen as the analog site because it has a secondary ore body that has formed over the past million years as a result of leaching by groundwater flowing through fractures in the primary ore body

  18. Multichannel analog temperature sensing system

    International Nuclear Information System (INIS)

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer

  19. Analog Input Data Acquisition Software

    Science.gov (United States)

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  20. Multichannel analog temperature sensing system

    Science.gov (United States)

    Gribble, R.

    1985-08-01

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer.

  1. Mexico Agriculture Policy Review

    OpenAIRE

    Cahill, Carmel; Jotanovic, Aleksandar; Abraham, Cally

    2008-01-01

    As a NAFTA partner and Canada's third largest export market for agri-food products, developments in Mexico are of direct interest to Canada. Rural poverty, low productivity, poor infrastructure and unclear property rights for both land and water still inhibit the efforts of Mexico's government to improve competitiveness of its agricultural sector.

  2. Efficiency analysis in the application of indicators LEED-ND, the arid zone of the north of Mexico, case of study: Parajes del Sur, Ciudad Juarez, Chihuahua; Analisis de la eficiencia en la aplicacion de indicadores LEED-ND, en la zona arida del norte de Mexico, caso de estudio: parajes del sur, Ciudad Juarez, Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Pena Barrera, Leticia [Universidad Autonoma de Ciudad Juarez, Chihuahua (Mexico)

    2009-01-15

    This article presents the analysis realized to the urban design of a colony applying the indicators of The Leadership in Energy (LEED-ND). The advantages that represent as far as impact are established and also the limits are pointed out, evaluating their efficiency in the application of indicators to improve performance and energy saving. Based on the analysis applied to the colony under study, some right solutions in the urban design are obtained that should be established as a part of the in force standardization. Nevertheless, the follow up to this same company in other developments, reflects that the proposals are not determined as a strategy of self planning but only to fulfill the asked requirements, obtaining a result with smaller impact and as an index that allows offering residential alternatives in the city tending to the sustained development. [Spanish] Este articulo presenta el analisis realizado al diseno urbano de un fraccionamiento aplicando los indicadores de The Leadership in Energy (LEED-ND). Se establecen las ventajas que presenta en cuanto a impacto y tambien se senalan las limitantes, evaluando su eficiencia en la aplicacion de indicadores para mejorar desempeno y ahorro energetico. Con base en el analisis aplicado al fraccionamiento en estudio, se tienen algunas soluciones acertadas en el diseno urbano que debieran establecerse como parte de la normatividad vigente, sin embargo, el seguimiento a esta misma empresa en otros desarrollos, refleja que las propuestas no estan determinadas como una estrategia de planeacion propia sino unicamente para cumplir con los requerimientos solicitados, obteniendo un resultado con menor impacto y como indice que permitan ofrecer alternativas habitacionales en la ciudad tendientes al desarrollo sostenido.

  3. Integrated geographic information systems (IGIS) analysis and definition of the tectonic framework of northern Mexico

    Science.gov (United States)

    Martinez Pina, Carlos Manuel

    Crustal rupture structures reactivated in the course of the tectonic history of northern Mexico are the surface expressions of planes of weakness, in the form of simple or composite rectilinear features or slightly curved, defined as lineaments. Unless otherwise defined as strike-slip faults, lineaments are part of parallel and sub-parallel oblique convergent or oblique divergent tectonic zones cross cutting the Sierra Madre Occidental and northern Mexico, in a NW trend. These shear zones are the response to the oblique subduction of the Farallon plate beneath North America. Kinematic analysis of five selected sites in northern Mexico, three basins and two compressional shear zones, proved possible a combination of shear mechanism diagram and models from analogue materials, with satellite imagery and geographic information systems, as an aid to define strike-slip fault motion. This was done using a reverse engineering process by comparing geometries. One of the sites assessed, involving the Parras Basin, Coahuila Block (CB), San Marcos fault, a postulated PBF-1 fault, allowed for palinpastic reconstruction of the CB that corroborated the results of the vector motion defined, in addition to an extension of ˜25% in a northwest southeast direction. A GIS-based compilation and georeferenced regional structural studies by several researchers were used as ground control areas (GCA); their interpolation and interpretation, resulted in a tectonic framework map of northern Mexico. In addition, shaded relief models overlaid by the lineaments / fault layer allowed structural analyses of basins related to these major structures. Two important results were obtained from this study: the Tepehuanes-San Luis-fault (TSL) and the Guadalupe fault, named herein, displaces the Villa de Reyes graben, and the Aguascalientes graben, respectively, to the SE, confirming their left lateral vector motion; afterwards TSL was displaced south by the right lateral strike slip Taxco-San Miguel de

  4. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  5. Synaptic dynamics in analog VLSI.

    Science.gov (United States)

    Bartolozzi, Chiara; Indiveri, Giacomo

    2007-10-01

    Synapses are crucial elements for computation and information transfer in both real and artificial neural systems. Recent experimental findings and theoretical models of pulse-based neural networks suggest that synaptic dynamics can play a crucial role for learning neural codes and encoding spatiotemporal spike patterns. Within the context of hardware implementations of pulse-based neural networks, several analog VLSI circuits modeling synaptic functionality have been proposed. We present an overview of previously proposed circuits and describe a novel analog VLSI synaptic circuit suitable for integration in large VLSI spike-based neural systems. The circuit proposed is based on a computational model that fits the real postsynaptic currents with exponentials. We present experimental data showing how the circuit exhibits realistic dynamics and show how it can be connected to additional modules for implementing a wide range of synaptic properties. PMID:17716003

  6. Mechanical Analogies of Fractional Elements

    Institute of Scientific and Technical Information of China (English)

    HU Kai-Xin; ZHU Ke-Qin

    2009-01-01

    A Fractional element model describes a special kind of viscoelastic material.Its stress is proportional to the fractional-order derivative of strain. Physically the mechanical analogies of fractional elements can be represented by spring-dashpot fractal networks. We introduce a constitutive operator in the constitutive equations of viscoelastic materials.To derive constitutive operators for spring-dashpot fractal networks, we use Heaviside operational calculus, which provides explicit answers not otherwise obtainable simply.Then the series-parallel formulas for the constitutive operator are derived. Using these formulas, a constitutive equation of fractional element with 1/2-order derivative is obtained.Finally we find the way to derive the constitutive equations with other fractional-order derivatives and their mechanical analogies.

  7. Bottomed analog of Z+(4433)

    International Nuclear Information System (INIS)

    The newly observed Z+(4433) resonance by BELLE is believed to be a tetraquark bound state made up of (cu)(cd). We propose the bottomed analog of this bound state, namely, by replacing one of the charm quarks by a bottom quark, thus forming Zbc0,±,±±. One of the Zbc is doubly charged. The predicted mass of Zbc is around 7.6 GeV. This doubly charged bound state can be detected by its decay into Bc±π±. Similarly, we can also replace both charm quark and antiquark of the Z+(4433) by bottom quark and antiquark, respectively, thus forming Zbb the bottomonium analog of Z+(4433). The predicted mass of Zbb is about 10.7 GeV

  8. Analog Nonvolatile Computer Memory Circuits

    Science.gov (United States)

    MacLeod, Todd

    2007-01-01

    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  9. PHASE ANALYSES OF URANIUM BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    International Nuclear Information System (INIS)

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions

  10. Census Snapshot: New Mexico

    OpenAIRE

    Romero, Adam P; Rosky, Clifford J; Badgett, M.V. Lee; Gates, Gary J.

    2008-01-01

    Using data from the U.S. Census Bureau, this report provides demographic and economic information about same-sex couples and same-sex couples raising children in New Mexico. We compare same-sex “unmarried partners,” which the Census Bureau defines as an unmarried couple who “shares living quarters and has a close personal relationship,” to different-sex married couples in New Mexico. In many ways, the more than 6,000 same-sex couples living in New Mexico are similar to married couple...

  11. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2007-01-01

    This Selected Issues paper analyzes external shocks and business cycle fluctuations in Mexico. The paper examines the relative importance of U.S. demand shocks—and other foreign disturbances—in explaining Mexican output fluctuations. It identifies the dynamic response of Mexico’s output to those shocks. The paper investigates which U.S. variables are most relevant to explaining business cycles in Mexico. It analyses potential spillovers and channels of transmission underlying the linkag...

  12. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2004-01-01

    This Selected Issues paper analyzes reserve adequacy in Mexico. Reserve adequacy has been of renewed interest, as the authorities have introduced a new rules-based mechanism of U.S. dollar sales to reduce the rate of reserve accumulation. The paper examines the recent experience with Mexico’s fiscal management tools in light of the need for further consolidation. It reviews evidence on the cyclical behavior of fiscal policy in Mexico, finding that it has generally been procyclical since the...

  13. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2013-01-01

    This Selected Issues paper analyzes reforms to Mexico’s fiscal framework. Mexico’s resilient economic performance would be consolidated by increasing fiscal policy buffers and preparing for challenges associated with long-term budget pressures. In the short term, reducing public debt levels can create space to implement countercyclical fiscal policies and reduce exposure to high financing and hedging costs, which would protect Mexico’s credit rating at times of distress. The paper highl...

  14. A Global Analog of Cheshire Charge

    OpenAIRE

    McGraw, Patrick

    1994-01-01

    It is shown that a model with a spontaneously broken global symmetry can support defects analogous to Alice strings, and a process analogous to Cheshire charge exchange can take place. A possible realization in superfluid He-3 is pointed out.

  15. Atheism and Analogy: Aquinas Against the Atheists

    OpenAIRE

    Linford, Daniel J.

    2014-01-01

    In the 13th century, Thomas Aquinas developed two models for how humans may speak of God - either by the analogy of proportion or by the analogy of proportionality. Aquinas's doctrines initiated a theological debate concerning analogy that spanned several centuries. In the 18th century, there appeared two closely related arguments for atheism which both utilized analogy for their own purposes. In this thesis, I show that one argument, articulated by the French materialist Paul-Henri Thiry Bar...

  16. Elaboración del duelo de una madre cuyo hijo trabajaba como sicario en Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Rosalía Delgado Durán

    2014-01-01

    Full Text Available El presente trabajo es parte de una investigación cualitativa sobre el proceso de ela - boración de duelo de la madre de un sicario en el contexto de una terapia Gestalt. Se utilizó para su análisis la perspectiva de las etapas del duelo de Kübler-Ross (2006:59- 119. La exacerbación de la violencia generada en buena medida por pugnas entre gru - pos del crimen organizado en Ciudad Juárez, Chihuahua (Martínez, 2008, ha dado como resultado una gran cantidad de muertes, una de ellas es el caso que nos ocupa. Si bien uno de los objetivos iniciales de la investigación era documentar y analizar las etapas en el desarrollo del duelo de una madre a partir del fallecimiento de su hijo, este se replanteó durante el transcurso de la misma, ya que una de las características del duelo de esta madre es que inició justo cuando se enteró del trabajo que él realizaba.

  17. 1973 Veracruz, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — South of Veracruz, southeastern Mexico. Damage: Severe. The earthquake caused heavy damage in the states of Morelos, Puebla, and Veracruz. Thousands were left...

  18. New Mexico Mountain Ranges

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Geographic Names Information System (GNIS) actively seeks data from and partnerships with Government agencies at all levels and other interested organizations....

  19. New Mexico Federal Lands

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer consists of federally owned or administered lands of the United States, Puerto Rico, and the U.S. Virgin Islands. Only areas of 640 acres or more are...

  20. Mexico - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Mexican Surface Daily Observations taken at 94 observatories located throughout Mexico, beginning in 1872 and going up through 1981. The data resided on paper...

  1. Occupational health in Mexico.

    Science.gov (United States)

    Carreón, Tania; Santos-Burgoa, Carlos; Baron, Sherry; Hernández, Sendy

    2002-01-01

    The authors discuss the maquiladoras and child labor, and offer an overview of the history of occupational safety and health in Mexico that covers laws and regulations, social security, unions, and enforcement of legislation. The organization and structure of the various institutions responsible for occupational safety and health (OSH), as well as administrative procedures, are described. This article concludes with a list of the new challenges for OSH in Mexico. PMID:12028953

  2. Doing Business in Mexico

    OpenAIRE

    Zimmermann, Thomas A.

    2002-01-01

    On 1 July 2001, a far-reaching free trade agreement between the EFTA States and Mexico entered into force. ”Doing Business in Mexico” provides targeted assistance to Swiss Small and Medium-Sized Enterprises (SME) that wish to tap the potential of Mexico as both an export destination and investment location. This comprehensive guide contains information and advice on market research, market entry, and investment in this fascinating country. Part I introduces the reader to this fascinating ...

  3. Privatization in Mexico

    OpenAIRE

    Chong, Alberto; Lopez-de-Silanes, Florencio

    2004-01-01

    Over the last 20 years, Mexico redefined the role of the state in its economy through an ambitious program to liberalize trade, promote efficiency and reduce the size and scope of the state-owned sector. In Mexico, privatization led to a significant improvement in firm performance, as profitability increased 24 percentage points and converged to levels similar to those of private firms. From this increase, at most 5 percent can be attributed to higher prices and 31 percent to transfers from w...

  4. Mexico; Selected Issues Paper

    OpenAIRE

    International Monetary Fund

    2010-01-01

    This Selected Issues paper analyzes the global crisis and potential growth in Mexico. The paper uses two methodologies to assess to what extent the global crisis is likely to weigh on Mexico’s growth potential. The first approach is sectoral, examining the historical relationship between financial stress and growth in manufacturing industries. The second approach uses a growth-accounting framework to take a closer look at likely developments in the factors that drive potential growth. The p...

  5. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2011-01-01

    Mexico’s growth process in trend and cyclical factors, with implications for policy decisions, is discussed. Mexico’s trade integration has been important for growth. But the high export growth experienced has been followed by a more muted performance. Reforms to improve productivity are important to sustain export dynamism. Fiscal credibility, underpinned by prudent fiscal management and a strong fiscal framework, permitted a countercyclical fiscal response during the global crisis. Howe...

  6. REDD+ i Mexico

    OpenAIRE

    Leithoff Christensen, Anneliese; Bondo Vester, Rasmus; Q. Madsen, Camilla Henriette

    2014-01-01

    Mexico joined the REDD+ program (Reducing emissions from deforestation and forest degradation) in 2010, and has since worked on the design of a national strategy to be implemented in the country. Through ACF's theoretical perspective, we analyze advocacy coalitions and belief systems of the actors in the subsystem in the design of Mexico's REDD+ national strategy. All coalitions in the subsystem share a deep core belief that REDD+ as vision has the potential to tackle deforestation problems. ...

  7. Poverty alleviation in Mexico

    OpenAIRE

    Levy, Santiago

    1991-01-01

    This paper is concerned with the problem of poverty in Mexico. Its four objectives are to : i) present evidence; ii) analyze economic determinants; iii) discuss policy options; and iv) assess existing poverty programs. The author begins by giving a very brief discussion of recent economic events, as these set the stage for poverty programs in the 1990's. The paper goes on to discuss the concept of poverty measurement. The author presents evidence of the extent of poverty in Mexico. He aims at...

  8. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  9. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  10. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  11. Classical analogy of Fano resonances

    International Nuclear Information System (INIS)

    We present an analogy of Fano resonances in quantum interference to classical resonances in the harmonic oscillator system. It has a manifestation as a coupled behaviour of two effective oscillators associated with propagating and evanescent waves. We illustrate this point by considering a classical system of two coupled oscillators and interfering electron waves in a quasi-one-dimensional narrow constriction with a quantum dot. Our approach provides a novel insight into Fano resonance physics and provides a helpful view in teaching Fano resonances

  12. 78 FR 72751 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to the Foreign...

    Science.gov (United States)

    2013-12-03

    ... pursuant to the Kingpin Act: Individuals PORTILLO TOLENTINO, Rodolfo, c/o SERVICIO AEREO LEO LOPEZ, S.A. DE... SERVICIO AEREO LEO LOPEZ, S.A. DE C.V., Chihuahua, Chihuahua, Mexico; Calle Septima No. 1401, Villa...

  13. Pathogenic Landscape of Transboundary Zoonotic Diseases in the Mexico-US Border Along the Rio Grande.

    Science.gov (United States)

    Esteve-Gassent, Maria Dolores; Pérez de León, Adalberto A; Romero-Salas, Dora; Feria-Arroyo, Teresa P; Patino, Ramiro; Castro-Arellano, Ivan; Gordillo-Pérez, Guadalupe; Auclair, Allan; Goolsby, John; Rodriguez-Vivas, Roger Ivan; Estrada-Franco, Jose Guillermo

    2014-01-01

    Transboundary zoonotic diseases, several of which are vector borne, can maintain a dynamic focus and have pathogens circulating in geographic regions encircling multiple geopolitical boundaries. Global change is intensifying transboundary problems, including the spatial variation of the risk and incidence of zoonotic diseases. The complexity of these challenges can be greater in areas where rivers delineate international boundaries and encompass transitions between ecozones. The Rio Grande serves as a natural border between the US State of Texas and the Mexican States of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. Not only do millions of people live in this transboundary region, but also a substantial amount of goods and people pass through it everyday. Moreover, it occurs over a region that functions as a corridor for animal migrations, and thus links the Neotropic and Nearctic biogeographic zones, with the latter being a known foci of zoonotic diseases. However, the pathogenic landscape of important zoonotic diseases in the south Texas-Mexico transboundary region remains to be fully understood. An international perspective on the interplay between disease systems, ecosystem processes, land use, and human behaviors is applied here to analyze landscape and spatial features of Venezuelan equine encephalitis, Hantavirus disease, Lyme Borreliosis, Leptospirosis, Bartonellosis, Chagas disease, human Babesiosis, and Leishmaniasis. Surveillance systems following the One Health approach with a regional perspective will help identifying opportunities to mitigate the health burden of those diseases on human and animal populations. It is proposed that the Mexico-US border along the Rio Grande region be viewed as a continuum landscape where zoonotic pathogens circulate regardless of national borders. PMID:25453027

  14. Pathogenic landscape of transboundary zoonotic diseases in the Mexico-US border along the Rio Grande

    Directory of Open Access Journals (Sweden)

    Maria Dolores Esteve-Gasent

    2014-11-01

    Full Text Available Transboundary zoonotic diseases, several of which are vector borne, can maintain a dynamic focus, and have pathogens circulating in geographic regions encircling multiple geopolitical boundaries. Global change is intensifying transboundary problems including the spatial variation of the risk and incidence of zoonotic diseases. The complexity of these challenges can be greater in areas where rivers delineate international boundaries and encompass transitions between ecozones. The Rio Grande serves as a natural border between the US State of Texas and the Mexican States of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. Not only millions of people live in this transboundary region but also a substantial movement of goods and people pass through it everyday. Moreover, it occurs over a region that functions as a corridor for animal migrations, and thus links the Neotropic and Nearctic biogeographic zones, with the latter being a known foci of zoonotic diseases. However, the pathogenic landscape of important zoonotic diseases in the south Texas-Mexico transboundary region remains to be fully understood. An international perspective on the interplay between disease systems, ecosystem processes, land use, and human behaviors is applied here to analyze landscape and spatial features of Venezuelan equine encephalitis, Hantavirus disease, Lyme Borreliosis, Leptospirosis, Bartonellosis, Chagas disease, human Babesiosis, and Leishmaniasis. Surveillance systems following the One Health approach with a regional perspective will help identifying opportunities to mitigate the health burden of those diseases on human and animal populations. It is proposed that the Mexico-US border, along the Rio Grande region be viewed as a continuum landscape where zoonotic pathogens circulate regardless of national borders.

  15. Approaches to synthetic platelet analogs.

    Science.gov (United States)

    Modery-Pawlowski, Christa L; Tian, Lewis L; Pan, Victor; McCrae, Keith R; Mitragotri, Samir; Sen Gupta, Anirban

    2013-01-01

    Platelet transfusion is routinely used for treating bleeding complications in patients with hematologic or oncologic clotting disorders, chemo/radiotherapy-induced myelosuppression, trauma and surgery. Currently, these transfusions mostly use allogeneic platelet concentrates, while products like lyophilized platelets, cold-stored platelets and infusible platelet membranes are under investigation. These natural platelet-based products pose considerable risks of contamination, resulting in short shelf-life (3-5 days). Recent advances in pathogen reduction technologies have increased shelf-life to ~7 days. Furthermore, natural platelets are short in supply and also cause several biological side effects. Hence, there is significant clinical interest in platelet-mimetic synthetic analogs that can allow long storage-life and minimum side effects. Accordingly, several designs have been studied which decorate synthetic particles with motifs that promote platelet-mimetic adhesion or aggregation. Recent refinement in this design involves combining the adhesion and aggregation functionalities on a single particle platform. Further refinement is being focused on constructing particles that also mimic natural platelet's shape, size and elasticity, to influence margination and wall-interaction. The optimum design of a synthetic platelet analog would require efficient integration of platelet's physico-mechanical properties and biological functionalities. We present a comprehensive review of these approaches and provide our opinion regarding the future directions of this research. PMID:23092864

  16. Analog computation with dynamical systems

    Science.gov (United States)

    Siegelmann, Hava T.; Fishman, Shmuel

    1998-09-01

    Physical systems exhibit various levels of complexity: their long term dynamics may converge to fixed points or exhibit complex chaotic behavior. This paper presents a theory that enables to interpret natural processes as special purpose analog computers. Since physical systems are naturally described in continuous time, a definition of computational complexity for continuous time systems is required. In analogy with the classical discrete theory we develop fundamentals of computational complexity for dynamical systems, discrete or continuous in time, on the basis of an intrinsic time scale of the system. Dissipative dynamical systems are classified into the computational complexity classes P d, Co-RP d, NP d and EXP d, corresponding to their standard counterparts, according to the complexity of their long term behavior. The complexity of chaotic attractors relative to regular ones leads to the conjecture P d ≠ NP d. Continuous time flows have been proven useful in solving various practical problems. Our theory provides the tools for an algorithmic analysis of such flows. As an example we analyze the continuous Hopfield network.

  17. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J. M

    2013-01-01

    This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

  18. Aprendizaje colaborativo mediado por TIC en la enseñanza universitaria: un acercamiento a las percepciones y experiencias de profesores y alumnos de la Universidad Autónoma de Chihuahua

    OpenAIRE

    Álvarez Olivas, Vania Carolina

    2015-01-01

    [ES]Esta tesis doctoral constituye un trabajo de investigación descriptivo en la disciplina de educación. El objetivo general ha sido conocer las percepciones de profesores y alumnos de la Universidad Autónoma de Chihuahua (México) sobre el aprendizaje colaborativo y la mediación de las TIC (Tecnologías de la Información y la Comunicación) en dicho proceso, así como sus experiencias de trabajo colaborativo. En primer lugar, se presenta una revisión teórica acerca de las temátic...

  19. La evolución espacial de los subcentros de empleo en Ciudad Juárez, Chihuahua (1994-2004): un análisis con indicadores de autocorrelación espacial global y local

    OpenAIRE

    César M. Fuentes; Vladimir Hernández

    2015-01-01

    El objetivo del artículo es identificar los subcentros de empleo total mediante el uso de indicadores de autocorrelación espacial global y local en Ciudad Juárez, Chihuahua, en el periodo 1994-2004. Esta metodología usa matrices de pesos espaciales e incorpo - ra la noción de unidades vecinas y no está limitada al criterio de contigüidad del método de doble umbral. La variable usada fue la densidad bruta de empleo total (manufactura, comercio y servicio) en los ...

  20. New Mexico Voting Precincts (2008)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains the New Mexico Voting Precinct Boundaries as of July 2006. It is in a vector digital shapefile created to show the voting precinct coverage...

  1. New Mexico State Forestry Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains boundaries of the New Mexico Forestry Districts, plus the names of the district offices. It is in a vector digital structure digitized from a...

  2. HSIP Hospitals in New Mexico

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Hospitals in New Mexico The term "hospital" ... means an institution which- (1) is primarily engaged in providing, by or under the supervision of physicians, to...

  3. New Mexico Property Tax Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This layer represents boundaries for New Mexico tax district "OUT" categories and incorporated/municipal "IN" categories as identified on the "Certificate of Tax...

  4. Automatic activation of categorical and abstract analogical relations in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

    2006-10-01

    We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy. PMID:17263066

  5. Relación entre consultas a urgencias por enfermedad respiratoria y contaminación atmosférica en Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Hernández-Cadena Leticia

    2000-01-01

    Full Text Available OBJETIVO: Analizar la relación entre las concentraciones ambientales de partículas de diámetro <=10 µm (PM10 y de ozono con el número diario de consultas al servicio de urgencias por enfermedades respiratorias agudas y asma en niños menores de 15 años, residentes de Ciudad Juárez, Chihuahua, México. MATERIAL Y MÉTODOS: Este estudio se realizó durante los años de 1998 y 1999, utilizando un diseño de tipo ecológico. Los datos atmosféricos se obtuvieron de la base de datos de la Agencia de Protección al Ambiente (EPA, provenientes de ocho estaciones de monitoreo ubicadas en Ciudad Juárez y en El Paso, Texas. Los datos de consultas al servicio de urgencias por causas respiratorias se obtuvieron de los registros médicos de dos hospitales del Instituto Mexicano del Seguro Social (IMSS, en Ciudad Juárez, Chihuahua, de julio de 1997 a diciembre de 1998. Los diagnósticos se clasificaron en dos grupos: a asma, y b infecciones respiratorias altas, conforme a la Clasificación Internacional de Enfermedades (CIE-9 o CIE-10. El análisis se realizó con la utilización de la metodología de series de tiempo que emplea regresión Poisson. RESULTADOS: Durante el periodo de estudio la media de 24 horas de PM10 fue de 34.46 µg/m³ (DE=17.99 y la media de los niveles de ozono fue de 51.60 partes por billón (ppb (DE=20.70. El modelo propuesto estima que un incremento de 20 µg/m³ en el promedio de 24 horas, en la exposición a PM10, se relaciona con un incremento de 4.97% (IC 95% 0.97-9.13 en las consultas por asma con un retraso de cinco días y con un incremento de 9% (IC 95% 1.8-16.8 cuando se considera a la exposición acumulada de cinco días anteriores. Respecto a enfermedades respiratorias altas se encontró un aumento de 2.95% en las consultas a urgencias por cada 20 µm/m³ de incremento en el promedio de 24 horas en la exposición a PM10. Se observó que el impacto de PM10 sobre las visitas de urgencia por asma fue más severo en

  6. QCD analogy for quantum gravity

    Science.gov (United States)

    Holdom, Bob; Ren, Jing

    2016-06-01

    Quadratic gravity presents us with a renormalizable, asymptotically free theory of quantum gravity. When its couplings grow strong at some scale, as in QCD, then this strong scale sets the Planck mass. QCD has a gluon that does not appear in the physical spectrum. Quadratic gravity has a spin-2 ghost that we conjecture does not appear in the physical spectrum. We discuss how the QCD analogy leads to this conjecture and to the possible emergence of general relativity. Certain aspects of the QCD path integral and its measure are also similar for quadratic gravity. With the addition of the Einstein-Hilbert term, quadratic gravity has a dimensionful parameter that seems to control a quantum phase transition and the size of a mass gap in the strong phase.

  7. Analysis of analogies used by science teachers

    Science.gov (United States)

    Dagher, Zoubeida R.

    Science teachers use analogies that display a rich variety of form and content. An account of science teacher analogies that relies solely on systems of analysis imported from other fields of inquiry tends to obscure the unique features of these analogies as they operate within classroom discourse. This study examines teachers' analogies in context and highlights some of their special characteristics. The purpose of this analysis is to increase our understanding of how analogies operate in naturalistic instructional settings and to generate new research questions about science teaching and learning in view of the broader dimensions of the curriculum.Science isa very human activity. It involves human actors and judgements, rivalries and antagonisms, mysteries and surprises, the creative use of metaphor and analogy. It is fallible, often uncertain, and sometimes creatively ambiguous [Lemke, 1990, p. 134].Received: 1 June 1993; Revised: 29 November 1993;

  8. Priming analogical reasoning with false memories.

    Science.gov (United States)

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems. PMID:25784574

  9. Propuesta de Rehabilitación Urbana para la Colonia Tarahumara en Ciudad Cuauhtémoc, Chihuahua, México.

    Directory of Open Access Journals (Sweden)

    Leticia Peña Barrera

    2015-03-01

    Full Text Available A lo largo de la historia de la fundación de las ciudades ha sido posible identificar diversas situaciones de vulnerabilidad, ocasionadas ya sea por la condición geográfica, la dependencia al centro (factores de lejanía, la toma de decisiones ajenas a la región o el desequilibrio sociopolítico derivado de una propuesta de desarrollo que no responde a las necesidades de la sociedad y provoca condiciones insostenibles. Esta problemática se agudiza en regiones con diferentes minorías (indígenas, que subsisten en las ciudades, y cuyos usos y costumbres no son considerados en los programas dirigidos para otorgarles beneficios, de manera que son ajenos a su idiosincrasia y modo de vida. El gobierno del Estado de Chihuahua, interesado en apoyar a comunidades tarahumaras o rarámuris, promueve la creación de la Colonia Tarahumara en la ciudad de Cuauhtémoc, donando en 2001 el terreno y el financiamiento para las primeras 50 viviendas en propiedad común, y así lograr su arraigo. En este trabajo se presenta la propuesta de reequipamiento urbano-ecológico de la Colonia Tarahumara, la cual fue presentada a la Fundación Tarahumara para la construcción de otras 50 unidades de vivienda, teniendo en cuenta factores determinantes de localización e identificación de las costumbres de la comunidad rarámuri, como también soluciones urbano-bioclimáticas, con el fin de que ésta pueda tener acceso a la financiación federal de la Sedesol y, por último, de contribuir al desarrollo sostenible de la comunidad tarahumara.

  10. Prevalencia de asma y otras enfermedades alérgicas en niños escolares de Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Barraza-Villarreal Albino

    2001-01-01

    Full Text Available Objetivo. Determinar la prevalencia y severidad del asma, de la rinitis y del eczema en escolares. Material y métodos. Estudio transversal efectuado entre abril de 1998 y mayo de 1999 en Ciudad Juárez, Chihuahua, México, a una muestra aleatoria de 6 174 niños de 53 escuelas. Se aplicó la metodología propuesta por el International Study of Asthma and Allergies in Childhood (ISAAC (etapas 1 y 2 para determinar la prevalencia y severidad del asma, rinitis y eczema. La información de prevalencia, tanto actual como acumulada para dichos padecimientos, se obtuvo mediante un cuestionario ya estandarizado y contestado por los padres de los niños. El diseño de la muestra se hizo por un muestreo mixto, en el cual se estratificó por nivel de contaminación ambiental. Se estimaron prevalencias actual y acumulada estratificando por grupo de edad, sexo, área e historia familiar de asma. Resultados. La prevalencia acumulada de asma por diagnóstico médico y sibilancia (silbidos fue de 6.8% (IC95% 6.2-7.4 y 20.% (IC95% 19.7-21.8, respectivamente; la prevalencia de sibilancia en los últimos 12 meses fue mayor en el grupo de 6-8 años que en el de 11-14 años(9.7% contra 5.8% (phttp://www.insp.mx/salud/index.html

  11. Cuatro siglos de variabilidad hidroclimática en el noroeste de Chihuahua, México, reconstruida con anillos de árboles

    Directory of Open Access Journals (Sweden)

    José Villanueva Díaz

    2015-01-01

    Full Text Available En el noroeste de Chihuahua, sitio Mesa de las Guacamayas, catalogada como “Área Natural Protegida” ( ANP para anidamiento de la cotorra serrana, se desarrolló una serie dendrocronológica con abeto Douglas ( Pseudotsuga menziesii con una extensión de 409 años (1600-2008. La cronología de anillo total mostró asociaciones signi - ficativas (r>0.40, p=0.000 con cronologías vecinas (no separadas más de 200 km, particularmente las ubicadas en la misma vertiente de la Sierra Madre Occidental ( SMO , lo que implica la influencia de patrones climáticos comunes, cuyos frentes húmedos impactan simultáneamente una extensa área del noroeste de México. Un análisis espectral de potencia indicó que los índices dendrocronológicos estuvieron afectados por ENSO y por otros patrones circuatorios, como se deduce de los picos espectrales dominantes (<10 años presentes en la cronología; también mostraron asociación significativa (r=0.52, n=111, p<0.000 con registros del PDSI para el suroeste de los Estados Unidos. Una reconstrucción de precipitación acumulada enero- julio para la misma región, mostró sequías prolongadas en los periodos 1772-1782, 1793-1803, 1999-2008 y perio - dos húmedos en 1742-1751 y 1809-1818. La proporción de años secos detectados en la reconstrucción, sugiere que existe 50% de probabilidad de su ocurrencia a nivel anual.

  12. Humboldt's works on Mexico

    Directory of Open Access Journals (Sweden)

    Ulrike Leitner

    2000-10-01

    Full Text Available Article in English, Abstracts in Spanish and English. Humboldt wrote about Mexico from the perspective of a scientific explorer and naturalist. His works include his diaries, the Essai politique sur le royaume de la Nouvelle-Espagne, the Tablas géograficas, the Vues des Cordillères and a geographic atlas. Concerning the scientific aspect, the lack of a section on Mexico in the Relation historique is not a real deficit, since this can be found in the Essai. But only the diaries and letters from the journey, both published by the Alexander-von-Humboldt Research Centre, Berlin, can be considered an adequate substitute.The following will show the origin of Humboldt's writings on Mexico, offer historical and bibliographical facts and present the publications "Beiträge zur Alexander von Humboldt-Forschung", as well as Humboldt’s handwritten estate as far as they are available to us.

  13. Analog circuit design scalable analog circuit design, high speed D/A converters, RF power amplifiers

    CERN Document Server

    Huijsing, Johan

    2007-01-01

    Preface. Part I: Scalable Analog Circuit Design. Introduction. Scalable High-Speed Analog Circuit Design; M. Vertregt, P. Scholtens. Scalable High Resolution Mixed Mode Circuit Design; R.J. Brewer. Scalable 'High Voltages' Integrated Circuit Design for XDSL Type of Applications; D. Rossi. Scalability of Wire-Line Analog Front-Ends; K. Bult. Reusable IP Analog Circuit Design; J. Hauptmann, A. Wiesbauer, H. Weinberger. Process Migration Tools for Analog and Digital Circuits; K. Francken, G. Gielen. Part II: High-Speed D/A Converters. Introduction. Introduction to High-Speed Digital-to-Analog Con

  14. Xampling: Compressed Sensing of Analog Signals

    OpenAIRE

    Mishali, Moshe; Eldar, Yonina C.

    2011-01-01

    Xampling generalizes compressed sensing (CS) to reduced-rate sampling of analog signals. A unified framework is introduced for low rate sampling and processing of signals lying in a union of subspaces. Xampling consists of two main blocks: Analog compression that narrows down the input bandwidth prior to sampling with commercial devices followed by a nonlinear algorithm that detects the input subspace prior to conventional signal processing. A variety of analog CS applications are reviewed wi...

  15. Analog to Digital Conversion in Physical Measurements

    OpenAIRE

    Kapitaniak, T.; Zyczkowski, K.; Feudel, U.; Grebogi, C.

    1999-01-01

    There exist measuring devices where an analog input is converted into a digital output. Such converters can have a nonlinear internal dynamics. We show how measurements with such converting devices can be understood using concepts from symbolic dynamics. Our approach is based on a nonlinear one-to-one mapping between the analog input and the digital output of the device. We analyze the Bernoulli shift and the tent map which are realized in specific analog/digital converters. Furthermore, we d...

  16. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2004-01-01

    This Selected Issues paper analyzes the sources of Mexico’s economic growth since the 1960s, and compares various decompositions of historical growth into trend and cyclical components. The role of the implied output gaps in the inflation process is assessed. The paper presents medium-term paths for GDP based on alternative productivity growth rates. The paper also describes the significant steps Mexico has taken to strengthen the structure of its public debt in recent years, both in terms ...

  17. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2012-01-01

    Mexico is an open economy with strong real and financial links to the rest of the world with risks of spillovers from global turbulence. Recent gains in market share in the U.S. manufacturing market are owed to improved relative unit labor costs and reemergence of a location advantage. Mexico’s current fiscal framework requires measures to offset the emerging challenges of a decline in oil revenues and the projected increase in health- and pensions-related spending. The sustained increase o...

  18. Firearms in New Mexico.

    OpenAIRE

    Wiktor, S. Z.; Gallaher, M M; Baron, R C; Watson, M E; Sewell, C M

    1994-01-01

    To determine the prevalence of firearm ownership and storage practices in New Mexico, we did a random-digit-dialing survey of New Mexico residents in October 1991. Of 200 households surveyed, 79 (40%) had 1 or more firearms in the home. Rural households were more likely than urban households to have firearms (44% versus 30%), and households with annual incomes of greater than $25,000 were more likely to have a firearm than households with incomes of $25,000 or less (41% versus 33%). Household...

  19. Robust hyperchaotic synchronization via analog transmission line

    Science.gov (United States)

    Sadoudi, S.; Tanougast, C.

    2016-02-01

    In this paper, a novel experimental chaotic synchronization technique via analog transmission is discussed. We demonstrate through Field-Programmable Gate Array (FPGA) implementation design the robust synchronization of two embedded hyperchaotic Lorenz generators interconnected with an analog transmission line. The basic idea of this work consists in combining a numerical generation of chaos and transmitting it with an analog signal. The numerical chaos allows to overcome the callback parameter mismatch problem and the analog transmission offers robust data security. As application, this technique can be applied to all families of chaotic systems including time-delayed chaotic systems.

  20. Development of the TLALOCNet GPS-Met Network in Northwestern Mexico: Supporting Continuous Water Vapor Observations of the North American Monsoon

    Science.gov (United States)

    Galetzka, J.; Feaux, K.; Cabral, E.; Salazar-Tlaczani, L.; Adams, D. K.; Serra, Y. L.; Mattioli, G. S.; Miller, M. M.

    2014-12-01

    TLALOCNet is a combined atmospheric and tectonic cGPS-Met network in Mexico designed for the investigation of climate, atmospheric processes, the earthquake cycle, and tectonics. While EarthScope-Plate Boundary Observatory (conterminous US, Alaska, Puerto Rico) is among the networks poised to become a nucleus for hemisphere-scale GPS observations, the completion of TLALOCNet at the end of 2015 will close a gap between PBO and other Latin American GPS networks that include COCONet (Central America, Caribbean, and Northern South America), CAnTO, CAP, and IGS extending from Alaska to Patagonia. The National Science Foundation funded the construction and operation of TLALOCNet, with significant matching funds and resources provided by the Universidad Nacional Autónoma de México (UNAM). The project will involve the construction or refurbishment of 38 cGPS-Met stations in Mexico built to PBO standards. The first three TLALOCNet stations were installed in the northern Mexican states of Sonora and Chihuahua in July 2014, following the North American Monsoon GPS Transect Experiment 2013. Together these observations better characterize critical components of water transport in the region. Data from these stations are now available through the UNAVCO data archive and can be downloaded from http://facility.unavco.org/data/dai2/app/dai2.html#. By the end of 2014, TLALOCNet data, together with complementary data from other regional cGPS networks in Mexico, will also be openly available through a Mexico-based data center. We will present the status of the project to date, including an overview of the station hardware, data communications, data flow, construction schedule, and science objectives. We will also present some of the challenges encountered, including regional logistics, shipping and importation, site security, and other issues associated with the construction and operation of a large continuous GPS network.

  1. Topical glaucoma therapy cost in Mexico.

    Science.gov (United States)

    Lazcano-Gomez, Gabriel; Hernandez-Oteyza, Alejandra; Iriarte-Barbosa, María José; Hernandez-Garciadiego, Carlos

    2014-04-01

    Glaucoma is an important cause of irreversible blindness that represents a significant economic burden; most direct costs of glaucoma are drug-related. We calculated the annual cost of some of the most commonly prescribed glaucoma medications in Mexico, according to their average wholesale price (AWP) and dose regimen. Annual costs ranged from USD4.97 for Imot 15 ml (timolol 0.5 %; Laboratorios Sophia) to USD675.39 for Alphagan 5 ml (brimonidine 0.2 %; Allergan, Inc.). β-Blockers were the least expensive glaucoma medications (range USD20.44-55.44). Alphagan 5 ml was 250 % more expensive than other selective α(2)-agonists. Of the carbonic anhydrase inhibitors, dorzolamide 2 % was less expensive than brinzolamide 1 % (USD326.91 vs. USD418.96). The annual cost for prostaglandin analogs ranged from USD235.58 for bimatoprost 0.03 % to USD337.78 for latanoprost 0.005 %. Some fixed combinations were less expensive than separate combinations. The average annual cost for all treatments increased by 27.87 ± 10.09 % between 2009 and 2012. Annual glaucoma therapy cost seems to be lower in Mexico than in other countries, due to a lower AWP, especially for some medications made by Mexican laboratories. PMID:23846765

  2. [Food security in Mexico].

    Science.gov (United States)

    Urquía-Fernández, Nuria

    2014-01-01

    An overview of food security and nutrition in Mexico is presented, based on the analysis of the four pillars of food security: availability, access, utilization of food, and stability of the food supply. In addition, the two faces of malnutrition in Mexico were analyzed: obesity and undernourishment. Data were gathered from the food security indicators of the United Nations's Food and Agriculture Organization, from the Mexican Scale of Food Security, and from the National Health and Nutrition Survey. Mexico presents an index of availability of 3 145 kilocalories per person per day, one of the highest indexes in the world, including both food production and imports. In contrast, Mexico is affected by a double burden of malnutrition: whereas children under five present 14% of stunt, 30% of the adult population is obese. Also, more than 18% of the population cannot afford the basic food basket (food poverty). Using perception surveys, people reports important levels of food insecurity, which concentrates in seven states of the Mexican Federation. The production structure underlying these indicators shows a very heterogeneous landscape, which translates in to a low productivity growth across the last years. Food security being a multidimensional concept, to ensure food security for the Mexican population requires a revision and redesign of public productive and social policies, placing a particular focus on strengthening the mechanisms of institutional governance. PMID:25649459

  3. New Mexico's Challenge 2000.

    Science.gov (United States)

    Price, Robert M.; And Others

    This report presents a comprehensive strategy developed by the New Mexico Education Technology Planning Committee to maximize resources in educational technology to achieve the long-range goals adopted for education in the state. Four basic strategies are recommended: (1) to forge relationships between schools and businesses, and partnerships…

  4. The Art of Mexico.

    Science.gov (United States)

    Saccardi, Marianne

    1997-01-01

    Provides an annotated bibliography of books for grades K and up which explores the folklore, poetry, fiction, and art of Mexico, and focuses on the Mayans and Aztecs and Diego Rivera and Frida Kahlo. Also suggests various research, reading, drama, music, social studies, physical education, and art activities and lists related videos and Internet…

  5. Mexico Policy Notes

    OpenAIRE

    World Bank

    2013-01-01

    This note presents an overview of Mexico's forthcoming reform agenda-from the World Bank's vantage point. It distills the main messages in the policy notes that make up this compendium. The purpose is not to provide definitive answers to the many policy questions likely to occupy the New Mexican administration, or to provide a comprehensive account of progress to date and policy recommenda...

  6. Electroacoustic Music in Mexico

    OpenAIRE

    Rodrigo Sigal

    2010-01-01

    Mexico has been an outsider to the electroacoustic music movement. Countries likeArgentina, Cuba and Chile were pioneers in establishing electronic music centers in thecontinent. This texts aim to illustrate briefly the story behind the first initiatives in Mexicoandthe actual situation and characteristics of the institutional electroacoustic music scene.

  7. Human Rickettsialpox, Southeastern Mexico

    OpenAIRE

    Zavala-Castro, Jorge E.; Zavala-Velázquez, Jorge E.; Peniche-Lara, Gaspar F.; Uicab, Justo E. Sulú

    2009-01-01

    The detection of Rickettsia akari in 2 human patients increased the diversity of rickettsioses affecting the public health in the southeast of Mexico. Rickettsialpox should be considered in the differential diagnosis with other febrile illnesses for the correct diagnosis and accurate treatment of this potential threat to human health.

  8. Novel Analog For Muscle Deconditioning

    Science.gov (United States)

    Ploutz-Snyder, Lori; Ryder, Jeff; Buxton, Roxanne; Redd. Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle; Fiedler, James; Ploutz-Snyder, Robert; Bloomberg, Jacob

    2011-01-01

    Existing models (such as bed rest) of muscle deconditioning are cumbersome and expensive. We propose a new model utilizing a weighted suit to manipulate strength, power, or endurance (function) relative to body weight (BW). Methods: 20 subjects performed 7 occupational astronaut tasks while wearing a suit weighted with 0-120% of BW. Models of the full relationship between muscle function/BW and task completion time were developed using fractional polynomial regression and verified by the addition of pre-and postflightastronaut performance data for the same tasks. Splineregression was used to identify muscle function thresholds below which task performance was impaired. Results: Thresholds of performance decline were identified for each task. Seated egress & walk (most difficult task) showed thresholds of leg press (LP) isometric peak force/BW of 18 N/kg, LP power/BW of 18 W/kg, LP work/BW of 79 J/kg, isokineticknee extension (KE)/BW of 6 Nm/kg, and KE torque/BW of 1.9 Nm/kg.Conclusions: Laboratory manipulation of relative strength has promise as an appropriate analog for spaceflight-induced loss of muscle function, for predicting occupational task performance and establishing operationally relevant strength thresholds.

  9. An Analog Computer for Electronic Engineering Education

    Science.gov (United States)

    Fitch, A. L.; Iu, H. H. C.; Lu, D. D. C.

    2011-01-01

    This paper describes a compact analog computer and proposes its use in electronic engineering teaching laboratories to develop student understanding of applications in analog electronics, electronic components, engineering mathematics, control engineering, safe laboratory and workshop practices, circuit construction, testing, and maintenance. The…

  10. Analogical Processes and College Developmental Reading

    Science.gov (United States)

    Paulson, Eric J.

    2014-01-01

    Although a solid body of research concerning the role of analogies in reading processes has emerged at a variety of age groups and reading proficiencies, few of those studies have focused on analogy use by readers enrolled in college developmental reading courses. The current study explores whether 232 students enrolled in mandatory (by placement…

  11. Several Forms of Fuzzy Analogical Reasoning

    OpenAIRE

    Bouchon-Meunier, B; Delechamp, J.; Marsala, C.; Rifqi, M.

    1997-01-01

    We present a general framework representing analogy, on the basis of a link between variables and measures of comparison between values of variables. This analogical scheme is proven to represent a common description of several forms of reasoning used in fuzzy control or in the management of knowledge-based systems, such as deductive reasoning, inductive reasoning or prototypical reasoning, gradual reasoning.

  12. A physical analogy to fuzzy clustering

    DEFF Research Database (Denmark)

    Jantzen, Jan

    2004-01-01

    This tutorial paper provides an interpretation of the membership assignment in the fuzzy clustering algorithm fuzzy c-means. The membership of a data point to several clusters is shown to be analogous to the gravitational forces between bodies of mass. This provides an alternative way to explain...... the algorithm to students. The analogy suggests a possible extension of the fuzzy membership assignment equation....

  13. Novel Gemini vitamin D3 analogs

    DEFF Research Database (Denmark)

    Okamoto, Ryoko; Gery, Sigal; Kuwayama, Yoshio;

    2014-01-01

    We have synthesized 39 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] analogs having two side chains attached to carbon-20 (Gemini) with various modifications and compared their anticancer activities. Five structure-function rules emerged to identify analogs with enhanced anticancer activity. One of thes...

  14. Analog simulation of the Josephson effects

    International Nuclear Information System (INIS)

    Analog circuit techniques can be used to advantage to simulate the Josephson effects in a superconductor-insulator-superconductor tunnel junction. Details of an electronic Josephson simulator are presented, and the advantages of analog techniques over their digital counterparts for this application are discussed. The simulation of a Josephson microwave mixer is used as an example

  15. Young Children's Analogical Reasoning in Science Domains

    Science.gov (United States)

    Haglund, Jesper; Jeppsson, Fredrik; Andersson, Johanna

    2012-01-01

    This exploratory study in a classroom setting investigates first graders' (age 7-8 years, N = 25) ability to perform analogical reasoning and create their own analogies for two irreversible natural phenomena: mixing and heat transfer. We found that the children who contributed actively to a full-class discussion were consistently successful at…

  16. Analogies in high school Brazilian chemistry textbooks

    Directory of Open Access Journals (Sweden)

    Rosária Justi

    2000-05-01

    Full Text Available This paper presents and discusses an analysis of the analogies presented by Brazilian chemistry textbooks for the medium level. The main aim of the analysis is to discuss whether such analogies can be said good teaching models. From the results, some aspects concerning with teachers' role are discussed. Finally, some new research questions are emphasised.

  17. Play with Language: Overextensions as Analogies.

    Science.gov (United States)

    Hudson, Judith; Nelson, Katherine

    1984-01-01

    Defines criteria to identify children's language overextensions and investigates how young children in the early stages of language acquisition rename objects analogically during a standardized play situation. Results indicate that analogic extensions are well within the capabilities of children from one year, eight months to two years, four…

  18. Using evidence on violence and injury prevention for policy development and decision making in Ciudad Juarez, Mexico.

    Science.gov (United States)

    Gutiérrez, Luis Alberto; Pacheco, Sergio; Juárez, Alethia Yurithzi; Palacios, Luis Alexandro; Cerqueira, Maria Teresa

    2012-05-01

    This report describes the implementation process and functional structure of the Observatory of Security and Citizen Conviviality of the Juarez Municipality (Observatorio de Seguridad y Convivencia Ciudadanas del Municipio de Juárez) in Chihuahua, Mexico, and discusses the most relevant lessons learned and main challenges in the near future. The Observatory, created in 2008, is a joint effort of the Juarez Municipal Government, Autonomous University of Ciudad Juarez (Universidad Autónoma de Ciudad Juárez), and the Pan American Health Organization. The Observatory's main objective is to propose strategies and public policy recommendations to prevent and control violence and injuries in the Juarez Municipality. Most key federal, state, and local agencies have joined this independent autonomous citizen-based initiative, feed the databases, and benefit from the information produced by a multisectoral, multidisciplinary approach. The Observatory contributes far more than the technical data provided and its facilitating functions. The clear results obtained in such a short time-as seen in the preliminary results of the case study on road injuries from January 2009 to July 2011-demonstrate the appropriateness of this course of action and should stimulate the creation of new observatories whenever and wherever needed. Lessons learned, as discussed here, can open the way to new endeavors, and current challenges show how much work remains to be done. PMID:22767036

  19. Relationship with multiple partners in university women: a comparative study in two institutions from the northwest of Mexico

    Directory of Open Access Journals (Sweden)

    Julio Alfonso Piña

    2009-03-01

    Full Text Available Objective: To identify what variables influence having multiple sexual partners.Methods: A cross-sectional study was carried out with 542 women of two higher education institutions from the northwest of Mexico, who answered a questionnaire measuring psychological variables underlying high-risk sexual behaviors. The data were analyzed with T-tests, Mann-Whitney U tests, and with a multiple linear regression.Results: A multiple linear regression analysis showed the following results: for women from Hermosillo, Sonora, the predictors of high-risk sexual behaviors were biological age, age of sexual debut, and one biological state - «I was physically excited»-, with those variables explaining 53.4% of the total variance; for women from Ciudad Juarez, Chihuahua, the predictors were biological age, and two types of biological states -«I was physically excited» and «I was under the influence of alcohol», explaining 20.8% of the total variance.Conclusions: The results underscore the need to design prevention programs directed to avoid HIV infection based on behavioral competencies training.

  20. PHASE ANALYSES OF URANIUM-BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    M. Ren; P. Goodell; A. Kelts; E.Y. Anthony; M. Fayek; C. Fan; C. Beshears

    2005-07-11

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions.

  1. Computational approaches to analogical reasoning current trends

    CERN Document Server

    Richard, Gilles

    2014-01-01

    Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

  2. Analog regulation of metabolic demand

    Directory of Open Access Journals (Sweden)

    Muskhelishvili Georgi

    2011-03-01

    Full Text Available Abstract Background The 3D structure of the chromosome of the model organism Escherichia coli is one key component of its gene regulatory machinery. This type of regulation mediated by topological transitions of the chromosomal DNA can be thought of as an analog control, complementing the digital control, i.e. the network of regulation mediated by dedicated transcription factors. It is known that alterations in the superhelical density of chromosomal DNA lead to a rich pattern of differential expressed genes. Using a network approach, we analyze these expression changes for wild type E. coli and mutants lacking nucleoid associated proteins (NAPs from a metabolic and transcriptional regulatory network perspective. Results We find a significantly higher correspondence between gene expression and metabolism for the wild type expression changes compared to mutants in NAPs, indicating that supercoiling induces meaningful metabolic adjustments. As soon as the underlying regulatory machinery is impeded (as for the NAP mutants, this coherence between expression changes and the metabolic network is substantially reduced. This effect is even more pronounced, when we compute a wild type metabolic flux distribution using flux balance analysis and restrict our analysis to active reactions. Furthermore, we are able to show that the regulatory control exhibited by DNA supercoiling is not mediated by the transcriptional regulatory network (TRN, as the consistency of the expression changes with the TRN logic of activation and suppression is strongly reduced in the wild type in comparison to the mutants. Conclusions So far, the rich patterns of gene expression changes induced by alterations of the superhelical density of chromosomal DNA have been difficult to interpret. Here we characterize the effective networks formed by supercoiling-induced gene expression changes mapped onto reconstructions of E. coli's metabolic and transcriptional regulatory network. Our

  3. Advances in Analog Circuit Design 2015

    CERN Document Server

    Baschirotto, Andrea; Harpe, Pieter

    2016-01-01

    This book is based on the 18 tutorials presented during the 24th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of efficient sensor interfaces and low-power RF systems. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development. ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing.

  4. Fostering Multilateral Involvement in Analog Research

    Science.gov (United States)

    Cromwell, Ronita L.

    2015-01-01

    International collaboration in space flight research is an effective means for conducting investigations and utilizing limited resources to the fullest extent. Through these multilateral collaborations mutual research questions can be investigated and resources contributed by each international partner to maximize the scientific benefits to all parties. Recently the international partners embraced this approach to initiate collaborations in ground-based space flight analog environments. In 2011, the International Analog Research Working Group was established, and later named the International Human Space Flight Analog Research Coordination Group (HANA). Among the goals of this working group are to 1) establish a framework to coordinate research campaigns, as appropriate, to minimize duplication of effort and enhance synergy; 2) define what analogs are best to use for collaborative interests; and 3) facilitate interaction between discipline experts in order to have the full benefit of international expertise. To accomplish these goals, HANA is currently engaged in developing international research campaigns in ground-based analogs. Plans are being made for an international solicitation for proposals to address research of common interest to all international partners. This solicitation with identify an analog environment that will best accommodate the types of investigations requested. Once selected, studies will be integrated into a campaign and implemented at the analog site. Through these combined efforts, research beneficial to all partners will be conducted efficiently to further address human risks of space exploration.

  5. Analogies: Explanatory Tools in Web-Based Science Instruction

    Science.gov (United States)

    Glynn, Shawn M.; Taasoobshirazi, Gita; Fowler, Shawn

    2007-01-01

    This article helps designers of Web-based science instruction construct analogies that are as effective as those used in classrooms by exemplary science teachers. First, the authors explain what analogies are, how analogies foster learning, and what form analogies should take. Second, they discuss science teachers' use of analogies. Third, they…

  6. "CEZAC 06": nueva variedad de ajo tipo Jaspeado para la región norte centro de México "CEZAC 06": new Jaspeado garlic cultivar for the northem-central region of Mexico

    Directory of Open Access Journals (Sweden)

    Manuel Reveles-Hernández

    2011-08-01

    Full Text Available Alrededor de 5 200 hectáreas de ajo son cultivadas en México donde la región norte centro, es una de las principales áreas productoras de esta hortaliza. La falta de variedades de ajo localmente adaptadas es una seria desventaja para los productores de ajo. En este reporte se mencionan las principales características agronómicas de "CEZAC 06", una nueva variedad de ajo disponible para los productores de los estados de Zacatecas, Aguascalientes, Durango, Chihuahua y Coahuila. Las principales ventajas de esta variedad son rendimientos más altos, bulbos consistentemente redondos, menor número de dientes por bulbo y maduración homogénea. En parcelas comerciales el rendimiento se ha mejorado en 9-17% y se han alcanzado rendimientos de hasta 30 t ha-1 con el uso de "CEZAC 06".About 5 200 hectares of garlic are cultivated in Mexico; the north-central region is one of the main producing areas of this vegetable. The lack of locally adapted varieties of garlic is a serious disadvantage for garlic producers. In this paper are mentioned the main agronomic characteristics of "CEZAC 06", a new garlic variety available for producers of Zacatecas, Aguascalientes, Durango, Chihuahua and Coahuila. The main advantages of this variety are higher yield, consistently round bulbs, fewer numbers of cloves per bulb and homogeneous maturation. In commercial plots, yield has improved in 9-17% and there have been achieved yields of up to 30 t ha-1 using "CEZAC 06".

  7. U.S.-Mexico energy

    International Nuclear Information System (INIS)

    This paper reports that while Mexico's petrochemical industry has grown rapidly, it now faces shortages both in investment funds and in supplies of basic petrochemicals due to a financial crisis in the 1980s. Mexico has undertaken a series of policy reforms aimed at encouraging foreign and private investment, but these efforts have generally failed to entice U.S. investment in Mexico. U.S. petrochemical companies have cited unfavorable market conditions, insufficient basic petrochemical capacity in Mexico, concern about the reversibility of Mexican reforms, inadequate Mexican protection of intellectual property rights, and lack of investment protection for U.S. businesses as impediments to investment in Mexico. Cooperation between the two nations in overcoming these obstacles could help U.S. petrochemical companies maintain their positions in a competitive global market, while at the same time provide Mexico with much needed capital investment and technological expertise

  8. Radon availability in New Mexico

    International Nuclear Information System (INIS)

    The New Mexico Bureau of Mines and Mineral Resources (NMBMMR) in cooperation with the Radiation Licensing and Registration Section of the New Mexico Environment Department (NMED) and the US Environmental Protection Agency (EPA) have been evaluating geologic and soil conditions that may contribute to elevated levels of indoor radon throughout New Mexico. Various data have been integrated and interpreted in order to determine areas of high radon availability. The purpose of this paper is to summarize some of these data for New Mexico and to discuss geologic controls on the distribution of radon. Areas in New Mexico have been identified from these data as having a high radon availability. It is not the intent of this report to alarm the public, but to provide data on the distribution of radon throughout New Mexico

  9. Acoustics lecturing in Mexico

    Science.gov (United States)

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  10. A perspective from Mexico.

    Science.gov (United States)

    López, Mario Henry Rodríguez-

    2008-04-01

    As Binder et al. describe in their article in this issue of the Journal, most of the work of National Public Health Institutes (NPHIs) falls into the category of public goods. This is certainly true for the National Institute of Public Health (Instituto Nacional de Salud Publica (INSP)) of Mexico. Our mission is to contribute to social equity by improving public health in Mexico and Latin America, through the generation of knowledge, innovation in health systems, and public health training. At INSP, we believe that public health is a collective responsibility and that the state has a primary role in promoting and protecting the population's health. Binder et al. have performed a service by drawing attention to the importance of NPHIs and the challenges associated with funding public goods functions. PMID:18368016

  11. ALARA development in Mexico

    International Nuclear Information System (INIS)

    Even though the ALARA philosophy was formally implemented in the early 1980's, to some extent, ALARA considerations already had been incorporated into the design of most commercial equipment and facilities based on experience and engineering development. In Mexico, the design of medical and industrial facilities were based on international recommendations containing those considerations. With the construction of Laguna Verde Nuclear Power Station, formal ALARA groups were created to review some parts of its design, and to prepare the ALARA Program and related procedures necessary for its commercial operation. This paper begins with a brief historical description of ALARA development in Mexico, and then goes on to discuss our regulatory frame in Radiation Protection, some aspects of the ALARA Program, efforts in controlling and reducing of sources of radiation, and finally, future perspectives in the ALARA field

  12. Photonic analog computing with integrated silicon waveguides

    CERN Document Server

    Dong, Jianji; Zheng, Aoleng; Zhang, Xinliang

    2014-01-01

    The spectra of silicon integrated waveguides are tailored to process analog computing (i.e.,differential and integral) in optical domain with huge bandwidth.With the theory of signal and system, we design some silicon integrated devices to implement photonic differentiator and optical differential equation solver. The basic principle is to tailor the spectra of silicon integrated waveguides to meet the requirements of analog computing circuits. These analog photonic integrated circuits are very promising in future computing systems with high speed, low cost, and compact size. We also plan to employ these basic computing units in more complex computing modules.

  13. Mexico and the CTBT

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear Test-Ban-Treaty (CTBT) is a treaty that prohibits all the nuclear explosions by anybody and in any place, either on the terrestrial surface, in the atmosphere, under the sea or underground. From the adoption of this Treaty by the United Nations, Mexico has had interest for its entrance in vigor, as integral part to assure the international peace. For this reason, our country signed the Treaty since it was open in September 24, 1996 and three years later ratified it, due to Mexico is part of the group of necessary countries for their entrance in vigor. During 13 years, the country has been committed and helped to the installation of monitoring stations, actions that allow the strengthening of the International System of Surveillance. The purpose of this work is to divulge the Treaty,its technologies and benefits; and also to diffuse the works realized by Mexico regarding the radionuclides monitoring station and noble gases both certified ones for the CTBT. Besides the radionuclides technology, Mexico has taken charge of the installation and operation of the seismic stations and hydro-acoustics that have been certified too. The radionuclides station Rn-44 located in Guerrero Negro, BCS has two technologies, an automated sampler of suspended particles in air brand Cinderella/ARAME and a noble gases system Sauna used for the particles detection of radioactive material gamma emitting and Xenon radioisotopes product of nuclear assays. Both technologies are transmitting data in real time to the International Center of Data. These technologies are shown in this work. (Author)

  14. Idle Youth in Mexico

    OpenAIRE

    de Hoyos, Rafael; Gutierrez Fierros, Carlos; Vargas M., J. Vicente

    2016-01-01

    The present study combines data from Mexico's employment surveys (Encuesta Nacional de Empleo and Encuesta Nacional de Ocupación y Empleo) with the country's official statistics on murder rates to create a state-level panel data set covering the period 1995 to 2013. Including most of the common controls identified by the literature, the results show that the rate of male youth ages 19 to 2...

  15. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2014-01-01

    This Selected Issues paper analyzes the impact of Mexico’s energy reform on hydrocarbons production. These reforms aim to increase oil and gas production by eliminating the state oil company’s (PEMEX) monopoly on exploration and production of hydrocarbons, while retaining the prime directive that these resources are the property of the Mexican nation. This paper focuses on the nature of reforms and what problems these reforms are addressing. It presents illustrative production scenarios f...

  16. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2002-01-01

    This Selected Issues paper assesses the potential financial vulnerabilities of the corporate sector in Mexico. It provides an overview of salient features of the Mexican corporate sector. The paper also presents the formal stress tests that estimate the potential effects of some macroeconomic and financial shocks, such as a sharp depreciation of the exchange rate, a sustained increase in interest rates, a slowdown in demand, and a prolonged international market closure on the corporate sector.

  17. Mexico's Fiscal Crisis

    OpenAIRE

    Looney, R.E.

    1987-01-01

    Socio-Economic Planning Sciences, vol. 21, no.6, 1987. Refereed Journal Article Mexico's current crisis has its origins in a number of structural conditions that developed in the 1970s. This paper examines one of these structural impediments, the country's fiscal disequilibrium. An empirical analysis of the country's tax structure indicates that there is ample scope for major tax reforms geared to introducing more responsiveness into the country's tax collection system. Given t...

  18. Mexico environmental services project

    OpenAIRE

    Comisión Nacional Forestal (CONAFOR)

    2007-01-01

    Metadata only record The Mexico Environmental Services Project aims to improve water quality, biodiversity, and carbon sequestration from areas with globally significant biodiversity. Eight pilot sites will be chosen to overlap with existing high-priority biodiversity conservation areas. The project objectives will be met through "(i) strengthening the capacity of CONAFOR, INE, community associations, and NGOs to increase flexibility and improve efficiency of existing service provision to ...

  19. Inequality in Mexico

    OpenAIRE

    Prát, Šárka

    2013-01-01

    This thesis project has the aim of analysing the development of inequality in Mexico, income redistribution, and future possibilities of investment into the educational system. Human capital is one of the determinants of economic growth. Although human capital includes health, education, and social capital, the major focus of this diploma thesis is on education. Education becomes a suitability criterion for employment in all sectors of industry. Everyone is rewarded for exercising the knowled...

  20. Doing Business in Mexico

    OpenAIRE

    World Bank; International Finance Corporation

    2006-01-01

    This report investigates the scope and manner of regulations that enhance business activity and those that constrain it. Quantitative indicators on business regulations and their enforcement have been created for 12 cities and states, which can now be compared with Mexico City, and to 154 countries around the world. The indicators cover four "Doing Business" topics: starting a business, registering property, getting credit and enforcing contracts. The 12 cities and states are: Aguascalientes,...

  1. Mobile exhibition in Mexico

    International Nuclear Information System (INIS)

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  2. Lessons from Natural Analog Studies for Geologic Disposal of High-Level Nuclear Waste (Invited)

    Science.gov (United States)

    Murphy, W. M.

    2009-12-01

    For over fifty years natural analog studies have provided lessons addressing scientific, technical, and social problems concerning geologic disposal of high-level nuclear waste. Idealized concepts for permanent disposal environments evolved from an understanding of the geological, geochemical and hydrological characteristics of analogous rocks including natural salt deposits (as advocated by the US National Academy of Sciences in 1957), ancient cratonic rocks (as investigated at Lac du Bonnet, Canada, Aspö, Sweden, and Vienne, France), and marine sedimentary rock formations (as studied at Mol, Belgium, and Bure, France). Additional multidisciplinary studies have been conducted at natural sites that bear characteristics analogous to potential repository systems, notably at natural uranium (and thorium) deposits including Poços de Caldas, Brazil, Alligator Rivers, Australia, Peña Blanca, Mexico, and Oklo, Gabon. Researchers of natural analogs for geologic disposal have addressed technical uncertainties regarding processes that have transpired over large time and space scales, which are generally inaccessible to laboratory studies. Principal questions for nuclear waste disposal include the geochemical stability and alteration rates of radionuclide bearing minerals and the mechanisms and rates of transport of radionuclides in groundwater. In their most direct applications, natural analogs studies have been devoted to testing specific models for repository performance and the experimental data that support those models. Parameters used in predictive performance assessment modeling have been compared to natural system data, including mineral solubilities, sorption coefficients, diffusion rates, and colloid transport properties. For example, the rate of uraninite oxidation and the natural paragenesis of uranium mineral alteration at Peña Blanca have been compared favorably to results of experimental studies of spent fuel alteration related to the proposed repository

  3. Photoresistance analog multiplier has wide range

    Science.gov (United States)

    Hartenstein, R. G.

    1965-01-01

    Photoactivated bridge facilitates equal performance of analog multipliers over a wide frequency range. The multiplier operates from direct current to an upper frequency limited by either the light source or the closed-loop amplifier.

  4. The Analog (Computer) As a Physiology Adjunct.

    Science.gov (United States)

    Stewart, Peter A.

    1979-01-01

    Defines and discusses the analog computer and its use in a physiology laboratory. Includes two examples: (1) The Respiratory Control Function and (2) CO-Two Control in the Respiratory System. Presents diagrams and mathematical models. (MA)

  5. An Electrical Analog Computer for Poets

    Science.gov (United States)

    Bruels, Mark C.

    1972-01-01

    Nonphysics majors are presented with a direct current experiment beyond Ohms law and series and parallel laws. This involves construction of an analog computer from common rheostats and student-assembled voltmeters. (Author/TS)

  6. Optical analog-to-digital converter

    Science.gov (United States)

    Vawter, G. Allen; Raring, James; Skogen, Erik J.

    2009-07-21

    An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

  7. Guía práctica para la elaboración del diagnóstico clínico criminológico (Chihuahua, México/Practical guide for the elaboration of the criminological clinical diagnosis (Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    José Luis Prieto Montes

    2012-01-01

    Full Text Available Criminological diagnosis is a report of a legal nature carried out by means of a dynamic process that allows the analyst to set hypotheses about the explanatory factors for the conduct of an offender. It is not a static evaluation, will be modifying as you are revealing features of behavior, personality disorders, environment, culture, family and socio-demographic characteristics of crime, planning level and the relationship victim - perpetrator.

  8. Implementing neural architectures using analog VLSI circuits

    OpenAIRE

    Maher, Mary Ann C.; DeWeerth, Stephen P.; Mahowald, Misha A.; Mead, Carver A.

    1989-01-01

    Analog very large-scale integrated (VLSI) technology can be used not only to study and simulate biological systems, but also to emulate them in designing artificial sensory systems. A methodology for building these systems in CMOS VLSI technology has been developed using analog micropower circuit elements that can be hierarchically combined. Using this methodology, experimental VLSI chips of visual and motor subsystems have been designed and fabricated. These chips exhibit behavior similar to...

  9. Pigeons, Rats, and Humans Show Analogous Misinformation

    OpenAIRE

    Garry, Maryanne; Harper, David N

    2009-01-01

    In three experiments, we show that pigeons, rats and humans can be influenced by misleading postevent information in ways analogous to findings in the human memory distortion literature. We used a delayed matching to sample analog of the eyewitness testimony procedure from Loftus et al.(1978), and varied the length of the delay between event and exposure to post event information(PEI). We also varied the nature of PEI so that it was consistent with the event information, inconsistent, or neut...

  10. Analog VLSI model of binaural hearing

    OpenAIRE

    Mead, Carver A.; Arreguit, Xavier; Lazzaro, John

    1991-01-01

    The stereausis model of biological auditory processing was proposed as a representation that encodes both binaural and spectral information in a unified framework. We describe a working analog VLSI chip that implements this model of early auditory processing in the brain. The chip is a 100 000-transistor integrated circuit that computes the stereausis representation in real time, using continuous-time analog processing. The chip receives two audio inputs, representing sou...

  11. Analogical Learning and Automated Rule Constructions

    Institute of Scientific and Technical Information of China (English)

    周哈阳

    1991-01-01

    This paper describes some experiments of analogical learning and automated rule construction.The present investigation focuses on knowledge acquisition,learning by analyogy,and knowledge retention.The developed system initially learns from scratch,gradually acquires knowledge from its environment through trial-and-error interaction,incrementally augments its knowledge base,and analogically solves new tasks in a more efficient and direct manner.

  12. AMiBA Wideband Analog Correlator

    CERN Document Server

    Li, Chao-Te; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; Ho, P T P; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar; Lien, Chun-Hsien; Wang, Huei; Wei, Ray-Ming; Yang, Chia-Hsiang; Peterson, Jeffrey B; Chang, Su-Wei; Huang, Yau-De; Hwang, Yuh-Jing; Kesteven, Michael; Koch, Patrick; Liu, Guo-Chin; Nishioka, Hiroaki; Umetsu, Keiichi; Wei, Tashun; Wu, Jiun-Huei Proty

    2010-01-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.

  13. AMiBA Wideband Analog Correlator

    OpenAIRE

    Li, Chao-Te; Kubo, Derek Y.; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; P. T. P. Ho; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar

    2010-01-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting c...

  14. AMiBA Wideband Analog Correlator

    Science.gov (United States)

    Li, Chao-Te; Kubo, Derek Y.; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; Ho, P. T. P.; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar; Lien, Chun-Hsien; Wang, Huei; Wei, Ray-Ming; Yang, Chia-Hsiang; Peterson, Jeffrey B.; Chang, Su-Wei; Huang, Yau-De; Hwang, Yuh-Jing; Kesteven, Michael; Koch, Patrick; Liu, Guo-Chin; Nishioka, Hiroaki; Umetsu, Keiichi; Wei, Tashun; Proty Wu, Jiun-Huei

    2010-06-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband intermediate frequency distribution, back-end signal processing, and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.

  15. Low Power Analog Design in Scaled Technologies

    CERN Document Server

    Baschirotto, A; Cocciolo, G; D’Amico, S; De Matteis, M; Delizia, P

    2009-01-01

    In this paper an overview on the main issues in analog IC design in scaled CMOS technology is presented. Decreasing the length of MOS channel and the gate oxide has led to undoubted advantages in terms of chip area, speed and power consumption (mainly exploited in the digital parts). Besides, some drawbacks are introduced in term of power leakage and reliability. Moreover, the scaled technology lower supply voltage requirement has led analog designers to find new circuital solution to guarantee the required performance.

  16. A review of EBMT using proportional analogies

    OpenAIRE

    Somers, Harold; Dandapat, Sandipan; Naskar, Sudip Kumar

    2009-01-01

    Some years ago a number of papers reported an experimental implementation of Example Based Machine Translation (EBMT) using Proportional Analogy. This approach, a type of analogical learning, was attractive because of its simplicity; and the papers reported considerable success with the method. This paper reviews what we believe to be the totality of research reported using this method, as an introduction to our own experiments in this framework, reported in a companion paper. We report first...

  17. Automated Integrated Analog Filter Design Issues

    OpenAIRE

    Karolis Kiela; Romualdas Navickas

    2015-01-01

    An analysis of modern automated integrated analog circuits design methods and their use in integrated filter design is done. Current modern analog circuits automated tools are based on optimization algorithms and/or new circuit generation methods. Most automated integrated filter design methods are only suited to gmC and switched current filter topologies. Here, an algorithm for an active RC integrated filter design is proposed, that can be used in automated filter designs. The algorithm is t...

  18. On the gravitational analog of electromagnetic induction

    International Nuclear Information System (INIS)

    Discussed are some aspects of the analogy between stationary gravitational and electromagnetic fields, in particular, the gravitational analog of the electromagnetic induction phenomenon. The point is that the field of forces influencing the test particle in the strict system of reference is similar to the field of forces influencing a charged particle in the stationary electromagnetic field. The effect proceeds from the equation of motion of a spinning extended body

  19. Analog modelling of obduction processes

    Science.gov (United States)

    Agard, P.; Zuo, X.; Funiciello, F.; Bellahsen, N.; Faccenna, C.; Savva, D.

    2012-04-01

    Obduction corresponds to one of plate tectonics oddities, whereby dense, oceanic rocks (ophiolites) are presumably 'thrust' on top of light, continental ones, as for the short-lived, almost synchronous Peri-Arabic obduction (which took place along thousands of km from Turkey to Oman in c. 5-10 Ma). Analog modelling experiments were performed to study the mechanisms of obduction initiation and test various triggering hypotheses (i.e., plate acceleration, slab hitting the 660 km discontinuity, ridge subduction; Agard et al., 2007). The experimental setup comprises (1) an upper mantle, modelled as a low-viscosity transparent Newtonian glucose syrup filling a rigid Plexiglas tank and (2) high-viscosity silicone plates (Rhodrosil Gomme with PDMS iron fillers to reproduce densities of continental or oceanic plates), located at the centre of the tank above the syrup to simulate the subducting and the overriding plates - and avoid friction on the sides of the tank. Convergence is simulated by pushing on a piston at one end of the model with velocities comparable to those of plate tectonics (i.e., in the range 1-10 cm/yr). The reference set-up includes, from one end to the other (~60 cm): (i) the piston, (ii) a continental margin containing a transition zone to the adjacent oceanic plate, (iii) a weakness zone with variable resistance and dip (W), (iv) an oceanic plate - with or without a spreading ridge, (v) a subduction zone (S) dipping away from the piston and (vi) an upper, active continental margin, below which the oceanic plate is being subducted at the start of the experiment (as is known to have been the case in Oman). Several configurations were tested and over thirty different parametric tests were performed. Special emphasis was placed on comparing different types of weakness zone (W) and the extent of mechanical coupling across them, particularly when plates were accelerated. Displacements, together with along-strike and across-strike internal deformation in all

  20. Earthquake Damage in Mexico City, Mexico, September 19, 1985

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On September 19, 1985, a magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 km2 area of Mexico City, 350 km from...

  1. Mexico: Rasgos de Su Historia. (Mexico: Highlights of Its History).

    Science.gov (United States)

    Orozco, Cecilio

    Intended for both teachers and students, this publication, written in Spanish, briefly traces Mexico's history from its Conquest in 1519 to the overthrow of Porfirio Diaz in 1910. The following are briefly discussed: Mexico's Conquest in 1519; events immediately after the fall of Tenochtitlan; the War for Independence; Texas' separation from…

  2. Aquifer recharge estimation at the Mesilla Bolson and Guaymas aquifer systems, Mexico

    International Nuclear Information System (INIS)

    Three unsaturated profiles were obtained from Mesilla Bolson and Guaymas aquifer systems, northern Mexico. About 500 mL of undisturbed soil from depths between 1 m and 58 m below the surface were obtained every meter by dry percussion from a borehole located near Cd Juarez, Chihuahua state. The other two boreholes were located in the southwestern portion of Sonora state; about 500 mL of undisturbed soil from depths 0-5.50 and 0- 8.50 m were obtained every 0.25 m by dry drilling at Narciso Mendoza and Guaymas sites, respectively. Samples were contained in sealed glass jars and analyzed for moisture content, chloride, deuterium and nitrate (NO3-N). The interstitial water was extracted by elution; chloride and nitrate were determined by automated colorimetry while deuterium by direct reduction. Considering an average precipitation at Mesilla Bolson area of 230 mm/year, a chloride rain content of 1 mg/L and a mean Cl content on the unsaturated profile of 977 mg/L below the zero flux plane, we estimated by the Cl mass balance approach a net palaeorecharge in the area of about 0.24 mm/year with a probable time scale profile of 11,000 years. For the Guaymas area the net recharge is in the range 0.11-0.16 mm/year, assuming an average rainfall of 320 mm/year, Cl rainfall content of 3.4 mg/L and mean Cl concentrations on the profiles of 6,939 and 9,470 mg/L below the zero flux plane, respectively. (author)

  3. Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico

    Science.gov (United States)

    Delgado-Gardea, Ma. Carmen E.; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Zavala-Díaz de la Serna, Francisco Javier; Eroza-de la Vega, Gilberto; Nevárez-Moorillón, Guadalupe Virginia; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, María del Carmen; Infante-Ramírez, Rocío

    2016-01-01

    Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05) and fecal (p < 0.001) coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009), whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB) phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates), Escherichia coli (2/7), and Enterobacter cloacae (1/3). In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks. PMID:27322297

  4. Producción científica en el estado de Chihuahua, 1999-2008: análisis de las publicaciones registradas por el ISI Web of Knowledge Scientific production in the state of Chihuahua, 1999-2008: analysis of publications registered by ISI Web of Knowledge

    Directory of Open Access Journals (Sweden)

    Faustino Moreno-Ceja

    2011-12-01

    Full Text Available Este trabajo de investigación se basa en las publicaciones producidas en una década por investigadores del estado de Chihuahua, México; el análisis es predominantemente cuantitativo y se llevó a cabo a través de técnicas bibliométricas teniendo como objetivo examinar la producción del conocimiento científico en el estado a partir de una revisión de los documentos incluidos en las bases de datos de la ISI Web of Knowledge durante 1999-2008. La metodología seguida se basó en la aplicación de indicadores bibliométricos tales como: producción, temática, tipología, idioma, colaboración, índice de coautoría, entre otros. En relación con los resultados se observó que la producción total reportada para el periodo estudiado fue de 973 documentos; se encontró que tan solo 10 instituciones tienen presencia en el total de la producción, las temáticas principales de publicación fueron Ciencia de los materiales (28.98%, seguida de Física (26.10%; la tipología preferida fue el artículo (60.64%, el idioma principal de publicación fue el inglés (93.53%; en relación con el indicador de colaboración, la mayor parte fue internacional (39.47%, donde el principal socio fue EUA (52.08%; la media de autores por documento fue de 4.66.This paper is based on the publications produced in a decade by researchers in the State of Chihuahua, México; the analysis is predominantly quantitative and was undertaken through bibliometric techniques, being its objective to examine the production of scientific knowledge in the state, considering as starting point the documents included in the database of ISI Web of Knowledge during 1999-2008. The methodology followed considered the application of bibliometric indicators such as: output, subject areas, typology, language, collaboration, number of authors contributing to each article, among others. Regarding output, it was observed that the total production reported for the period under study was of

  5. Optical domain analog to digital conversion methods and apparatus

    Science.gov (United States)

    Vawter, Gregory A

    2014-05-13

    Methods and apparatus for optical analog to digital conversion are disclosed. An optical signal is converted by mapping the optical analog signal onto a wavelength modulated optical beam, passing the mapped beam through interferometers to generate analog bit representation signals, and converting the analog bit representation signals into an optical digital signal. A photodiode receives an optical analog signal, a wavelength modulated laser coupled to the photodiode maps the optical analog signal to a wavelength modulated optical beam, interferometers produce an analog bit representation signal from the mapped wavelength modulated optical beam, and sample and threshold circuits corresponding to the interferometers produce a digital bit signal from the analog bit representation signal.

  6. Aplicación de técnicas de ciclo de vida al diseño de un sistema de gestión de residuos urbanos para la ciudad de chihuahua

    OpenAIRE

    Gómez Méndez, Maria Guadalupe

    2009-01-01

    La gestión de los residuos sólidos en los municipios es un aspecto importante para la protección de la salud y el medioambiente. La generación de residuos sólidos aumenta al aumentar la población, a la vez varia la composición por la actividad humana, ubicación geográfica, estilo de vida, etc. El estudio se divide en dos secciones, la primera es la caracterización de los residuos sólidos urbanos domiciliarios en la ciudad de Chihuahua y la segunda parte es la evaluación ambiental de posibles...

  7. Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End

    Science.gov (United States)

    Prokop, Norman; Krasowski, Michael

    2013-01-01

    This innovation is capable of correlating two analog signals by using an analog-based signal conditioning front end to hard-limit the analog signals through adaptive thresholding into a binary bit stream, then performing the correlation using a Hamming "similarity" calculator function embedded in a one-bit digital correlator (OBDC). By converting the analog signal into a bit stream, the calculation of the correlation function is simplified, and less hardware resources are needed. This binary representation allows the hardware to move from a DSP where instructions are performed serially, into digital logic where calculations can be performed in parallel, greatly speeding up calculations.

  8. Mexico: Democracy and the Future

    Science.gov (United States)

    Bruhn, Kathleen

    2009-01-01

    During most of the twentieth century, Mexico was governed by one of the longest-ruling authoritarian parties in the contemporary world. Even as most Latin American countries democratized in the 1980s, Mexico remained under the control of the Institutional Revolutionary Party (PRI). It was not until the 2000 presidential election that a two-party…

  9. Mexico's National Educational Videoconferencing Network.

    Science.gov (United States)

    Pisanty, Alejandro

    This paper begins with background on the National University of Mexico (UNAM) and its networks. Other distance education projects in Mexico are described, including projects of the Instituto Politecnico Nacional (IPN), the National Distance Education Program operated by the Secretary of Education, and the Instituto Tecnologico y de Estudios…

  10. Mosses new to New Mexico

    Science.gov (United States)

    A bryophyte inventory was conducted in the Valles Caldera National Preserve (VCNP), New Mexico, from 2009 to 2011. Specimens representing 113 species of bryophytes were collected. Of those bryophytes, seven of the mosses were new to New Mexico: Atrichum tenellum (Rohling) Bruch & Schimper, Dicranum ...

  11. Soil-geomorphology and “wet” cycles in the Holocene record of North-Central Mexico

    Science.gov (United States)

    Butzer, Karl W.; Abbott, James T.; Frederick, Charles D.; Lehman, Paul H.; Cordova, Carlos E.; Oswald, John F.

    2008-10-01

    The distinction between the impact of climatic periodicities or land-use practices on soil erosion is an important issue for Pre-Hispanic and Colonial Mexico. That question can best be addressed by first documenting the dynamics of changing "wet" cycles during the Holocene in the central Mexican region between the northern limits of Pre-Hispanic agriculture and its southern margins in northwestern Chihuahua. Consequently the Laguna Project targeted a 125,000 km 2 sector of North-Central Mexico, 250 km from north to south and 500 km from east to west, from Saltillo to Durango. Some 40 sedimentary profiles with multiple cumulic soils were studied in the field and laboratory, supported by 163 conventional 14C and AMS dates on charcoal and soil humates. We distinguish: (1) wet floodplains (with humic paleosols, redox phenomena reflecting high water tables, channel-ponding sequences, and interbedded tufas) that imply aquifer recharge, sustained base flow, and mainly low-energy conditions; and (2) high-energy pulses of discharge that mobilized cobble gravels or forced channel entrenchment ("gullying") and were tied to episodic, excessive rains that promoted valley and slope instability. In between such "wet" cycles and recurrent disequilibrium events, climate was similar to today, probably less humid, with limited geomorphologic change or slow soil formation. "Wet" cycles were rare at the end of the Pleistocene, but prominent during the Holocene. Disequilibrium proxies became common and dramatic after 2500 BP. The drainages from the Eastern and Western Sierra Madres responded in phase, but varied in detail. Around AD 1050-1200 "natural" erosion led to loss of soil organic carbon, as alternating severe droughts and heavy rains destroyed the ground cover and led to ecological aridification, well before arrival of Spanish miners and settlers. The evidence that human activity triggered Pre-Hispanic or Colonial erosion in Central Mexico should therefore be re

  12. Mexico: Imports or exports?

    International Nuclear Information System (INIS)

    This presentation provides an overview of Mexico's energy sector. Proven oil reserves place Mexico in ninth position in the world and fourth largest in natural gas reserves. Energy is one of the most important economic activities of the country, representing 3 per cent of Gross Domestic Product (GDP). Oil exports represent 8.4 per cent of total exports. Approximately 40 per cent of total public investment is earmarked for energy projects. The author discusses energy resources and energy sector limitations. The energy sector plan for the period 2001-2006 is discussed. Its goals are to ensure energy supply, to develop the energy sector, to stimulate participation of Mexican enterprises, to promote renewable energy sources, and to strengthen international energy cooperation. The regulatory framework is being adapted to increase private investment. Some graphs are presented, displaying the primary energy production and primary energy consumption. Energy sector reforms are reviewed, as are electricity and natural gas reforms. The energy sector demand for 2000-2010 and investment requirements are reviewed, as well as fuel consumption for power generation. The author discusses the National Pipeline System (SNG) and the bottlenecks caused by pressure efficiency in the northeast, flow restriction on several pipeline segments, variability of the Petroleos Mexicanos (PEMEX) own use, and pressure drop on central regions. The entire prospect for natural gas in the country is reviewed, along with the Strategic Gas Program (PEG) consisting of 20 projects, including 4 non-associated natural gas, 9 exploration and 7 optimization. A section dealing with multiple service contracts is included in the presentation. The authors conclude by stating that the priority is a national energy policy to address Mexico's energy security requirements, to increase natural gas production while promoting the diversification of imports, and a regulatory framework to be updated in light of current

  13. Natural gas in Mexico

    International Nuclear Information System (INIS)

    A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

  14. Environmental lead in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Albert, L.A.; Badillo, F. (Centro de Ecodesarrollo (Mexico))

    1991-01-01

    From the data presented here, it can be concluded that environmental exposure to lead is a particularly severe problem in Mexico. As has been shown, there are very important sources of exposure to this metal: (a) for rural populations who manufacture and/or utilize lead-glazed pottery, (b) for urban populations who are exposed to high air lead concentrations due to the continued use of lead fuel additives, (c) for workers of several industries, mainly those of batteries and pigments, (d) for consumers who routinely eat canned foods such as hot peppers and fruit products, and (e) for the general population living in the vicinity of smelters, refineries and other industries that emit lead. Therefore, in Mexico only those native populations living in very primitive communities, far away from all civilized life, could be expected to be free from this exposure. At the same time, and despite the relatively few data available, it can be stated that the exposure to lead of populations in Mexico could be approaching levels that might be highly hazardous, in particular for the neuropsychological health of children. Regarding the presence of lead in the environment, despite the fact that the available studies are not enough, it is evident that pollution by this metal is widespread and that there is a serious lack of studies for most regions of the country, including several that might be expected to be highly polluted. At the same time, it is evident that the official attention paid to the problem, either in regulations, support of further studies, or implementation of effective control measures has been far from the level needed according to the available data.

  15. 77 FR 76624 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to the Foreign...

    Science.gov (United States)

    2012-12-28

    .... LOPEZ FERNANDEZ, Juan Manuel), c/o SERVICIO AEREO LEO LOPEZ, S.A. DE C.V., Chihuahua, Chihuahua, Mexico..., Noemi; a.k.a. LOPEZ FERNANDEZ, Nohemi), c/o SERVICIO AEREO LEO LOPEZ, S.A. DE C.V., Chihuahua, Chihuahua....k.a. LOPEZ GRAYEB, Leopoldo Antonio), c/o SERVICIO AEREO LEO LOPEZ, S.A. DE C.V.,...

  16. Juvenile Justice in Mexico

    OpenAIRE

    Martha Frías Armenta; Livier Gómez Martínez

    2014-01-01

    The first tribunal in Mexico was established in the central state of San Luis Potosi in 1926. The Law Regarding Social Prevention and Juvenile Delinquency for the Federal District and Mexican territories was promulgated in 1928. In 2005, Article 18 of the Mexican Constitution was modified to establish a comprehensive system (“Sistema Integral de justicia†in Spanish) of justice for juveniles between 12 and 18 years old who had committed a crime punishable under criminal law. Its objective ...

  17. Mexico 68: Official Report

    OpenAIRE

    2014-01-01

    Intitulé “Mexico 68”, le rapport officiel publié en 1969 atteint un nouveau record avec plus de 2300 pages. Il se compose de quatre principaux volumes (Le pays ; L’organisation ; Les Jeux sportifs ; L’Olympiade culturelle) auxquels s’ajoute un coffret contenant divers souvenirs : médailles, tickets, cartes postales. Ce « cinquième volume » est assez méconnu. Le rapport officiel a été publié en 4 langues, sous la forme de deux éditions bilingues français-anglais et espagnol-allemand. Vol.1 Par...

  18. [Psychiatry in ancient Mexico].

    Science.gov (United States)

    Calderón Narváez, G

    1992-12-01

    Using studies on prehispanic and early post-conquest documents of Ancient Mexico--such as the Badianus Manuscript, also known as Libellus de Medicinalibus Indorum Herbis, and Brother Bernardino de Sahagún's famous work History of the Things of the New Spain, a description of some existing medical and psychiatric problems, and treatments Ancient Aztecs resorted to, is presented. The structure of the Aztec family, their problems with the excessive ingestion of alcoholic beverages, and the punishments native authorities had implemented in order to check alcoholism up are also described. PMID:1341125

  19. Port of Altamira, Mexico

    OpenAIRE

    Croonen, K.; Froeling, D.; Marbus, G.; Bemmel, M. van

    2006-01-01

    Master project report. The Port of Altamira is one of the fast growing ports in the world and is together with Veracruz and Coatzacoalcos one of the biggest ports of Mexico at the Gulf coast. It is an industrial Port with a lot of potential for expanding. However, the breakwaters of the Port extending into the sea caused severe erosion at the downdrift side of the Port (south side). This ongoing erosion is threatening a precious lagoon and some important land. The erosion can also cause a bre...

  20. [Health technology in Mexico].

    Science.gov (United States)

    Cruz, C; Faba, G; Martuscelli, J

    1992-01-01

    The features of the health technology cycle are presented, and the effects of the demographic, epidemiologic and economic transition on the health technology demand in Mexico are discussed. The main problems of science and technology in the context of a decreasing scientific and technological activity due to the economic crisis and the adjustment policies are also analyzed: administrative and planning problems, low impact of scientific production, limitations of the Mexican private sector, and the obstacles for technology assessment. Finally, this paper also discusses the main support strategies for science and technology implemented by the Mexican government during the 1980s and the challenges and opportunities that lie ahead. PMID:1411774

  1. 76 FR 58772 - Safety & Security Trade Mission; Mexico City and Monterrey, Mexico

    Science.gov (United States)

    2011-09-22

    ... International Trade Administration Safety & Security Trade Mission; Mexico City and Monterrey, Mexico AGENCY... Safety and Security trade mission to Mexico City and Monterrey, Mexico, for January 30-February 2, 2012... traveling to Mexico independently, will enhance the companies' ability to secure meetings with...

  2. The future of vitamin D analogs

    Directory of Open Access Journals (Sweden)

    Carlien eLeyssens

    2014-04-01

    Full Text Available The active form of vitamin D3, 1,25-dihydroxyvitamin D3, is a major regulator of bone and calcium homeostasis. In addition, this hormone also inhibits the proliferation and stimulates the differentiation of normal as well as malignant cells. Supraphysiological doses of 1,25-dihydroxyvitamin D3 are required to reduce cancer cell proliferation. However, these doses will lead in vivo to calcemic side effects such as hypercalcemia and hypercalciuria. During the last 25 years, many structural analogs of 1,25-dihydroxyvitamin D3 have been synthesized by the introduction of chemical modifications in the A-ring, central CD-ring region or side chain of 1,25-dihydroxyvitamin D3 in the hope to find molecules with a clear dissociation between the beneficial antiproliferative effects and adverse calcemic side effects. One example of such an analog with a good dissociation ratio is calcipotriol (DaivonexR, which is clinically used to treat the hyperproliferative skin disease psoriasis. Other vitamin D analogs were clinically approved for the treatment of osteoporosis or secondary hyperparathyroidism. No vitamin D analog is currently used in the clinic for the treatment of cancer although several analogs have been shown to be potent drugs in animal models of cancer. Omics studies as well as in vitro cell biological experiments unraveled basic mechanisms involved in the antineoplastic effects of vitamin D and its analogs. 1,25-dihydroxyvitamin D3 and analogs act in a cell type- and tissue-specific manner. Moreover, a blockade in the transition of the G0/1 towards S phase of the cell cycle, induction of apoptosis, inhibition of migration and invasion of tumor cells together with effects on angiogenesis and inflammation have been implicated in the pleiotropic effects of 1,25-dihydroxyvitamin D3 and its analogs. In this review we will give an overview of the action of vitamin D analogs in tumor cells and look forward how these compounds could be introduced in the

  3. Identificación de asentamientos irregulares y diagnóstico de sus necesidades de infraestructura en Ciudad Juárez, Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Iván Elías Ruiz Hernández

    2015-01-01

    écnicas de percepción remota, análisis espacial e información censal. Los atributos físicos incluyen las condiciones del terreno, disección vertical y zonas de riesgo geológico y de inundación. Los atributos socioeconómicos incluyen, polígonos de pobreza, cobertura de agua potable y drenaje, nivel de hacinamiento, relación centro-periferia y valor del suelo. Los atributos de organiza - ción espacial y tipo de materiales de construcción, fueron re - cabados de imágenes satelitales de alta resolución y métricas de paisaje. Estos tres grupos de variables fueron integrados en un modelo multicriterio para la identificación de AI en Ciudad Juárez, Chihuahua, México. El modelo permite no solo la identificación de dichos AI sino también la realización de un diagnóstico de sus necesidades de infraestructura y servicios urbanos contando con un nivel de exactitud del 97.66%. Esta investigación presenta un método nuevo y confiable para la identificación de AI y a su vez los resultados obtenidos proveen una importante herramienta para los responsables del desarrollo urbano en la toma de decisiones

  4. Morphostructural characterization of the Charco basin and its surrounding areas in the Chihuahua segment of north Mexican Basin and Range Province

    Science.gov (United States)

    Troiani, Francesco; Menichetti, Marco

    2014-05-01

    The Chihuahua Basin and Range (CBR) is the eastern branch of the northern Mexican Basin and Range Province that, from a morphostructural point of view, presently is one amongst the lesser-known zones of the southern portion of the North America Basin and Range Province. The study area covers an approximately 800 km2-wide portion of the CBR and encompasses the fault-bounded Charco basin and its surrounding areas. The bedrock of the area pertains to the large siliceous-igneous province of the Sierra Madre Occidental and consists of volcanoclastic rocks including Oligocene dacite, rhyolite, rhyolitic tuffs, and polimitic conglomerates. The region is characterized by a series of NW-SE oriented valleys delimited by tilted monoclinal blocks bounded by high angle, SW-dipping, normal faults. Abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins are the main morphological elements of the area. The valleys correspond to structural grabens filled with Plio-Pleistocene continental sediments. These grabens are about 10 km wide, while the extensional fault system extend over a distance of more than 15 km. The mountain ranges are in most cases continuous over distances that range from 10 to 70 km including different branches of the extensional and transfer faults. The morphogenesis is mainly erosive in character: erosional landforms (such as rocky scarps, ridges, strath-terraces, erosional pediment, reverse slopes, landslide scar zones, litho-structural flat surfaces) dominate the landscape. In contrast, Quaternary depositional landforms are mainly concentrated within the flat valleys or basins. The Quaternary deposits consist of wide alluvial fans extending to the foot of the main ridges, fluvial and debris-slope deposits. The morphostructural characterization of the area integrated different methodologies, including: i) geomorphological and structural field analyses; ii) remote sensing and geo-morphometric investigations

  5. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    Directory of Open Access Journals (Sweden)

    Troco K. Mihali

    2010-07-01

    Full Text Available Saxitoxin (STX and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs. PSTs are the causative agents of paralytic shellfish poisoning (PSP and are mostly associated with marine dinoflagellates (eukaryotes and freshwater cyanobacteria (prokaryotes, which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

  6. Analog forecasting with dynamics-adapted kernels

    Science.gov (United States)

    Zhao, Zhizhen; Giannakis, Dimitrios

    2016-09-01

    Analog forecasting is a nonparametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from kernel methods developed in harmonic analysis and machine learning and state-space reconstruction for dynamical systems. A key ingredient of our approach is to replace single-analog forecasting with weighted ensembles of analogs constructed using local similarity kernels. The kernels used here employ a number of dynamics-dependent features designed to improve forecast skill, including Takens’ delay-coordinate maps (to recover information in the initial data lost through partial observations) and a directional dependence on the dynamical vector field generating the data. Mathematically, our approach is closely related to kernel methods for out-of-sample extension of functions, and we discuss alternative strategies based on the Nyström method and the multiscale Laplacian pyramids technique. We illustrate these techniques in applications to forecasting in a low-order deterministic model for atmospheric dynamics with chaotic metastability, and interannual-scale forecasting in the North Pacific sector of a comprehensive climate model. We find that forecasts based on kernel-weighted ensembles have significantly higher skill than the conventional approach following a single analog.

  7. 21 CFR 808.81 - New Mexico.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false New Mexico. 808.81 Section 808.81 Food and Drugs... and Local Exemptions § 808.81 New Mexico. The following New Mexico medical device requirement is... from preemption under section 521(b) of the act: New Mexico Statutes Annotated, section 67-36-16(F)....

  8. the case of Mexico

    Directory of Open Access Journals (Sweden)

    D. Martínez Carrera

    2005-01-01

    Full Text Available Food products require efficient marketing systems to move from producers to consumers keeping high quality and price. In many developing countries, although mushroom production is well established and increasing, the marketing systems are poorly understood. During 1999-2004, we studied the channels of distribution for wild and cultivated mushrooms in central Mexico following an institutional approach (550 interviews. Most wild and cultivated mushrooms are marketed within this region. Representative places were selected for this study: a large city (Mexico, two medium cities (Puebla, Toluca, and a rural community (Cuetzalan. Several marketing channels were identified and described, involving middlemen, wholesalers, retailers, “tianguis”, public markets, retail food stores, and food services. The grower’s share, the gatherer’s share, and the mushroom marketing margin were also estimated. The present mushroom marketing system evolved from a small centralized process to a combination of centralized and decentralized marketing processes involving limited activities. During this series of changes, large private enterprises took over several marketing functions supporting the decentralization process, but discouraging the development of new firms specialized in mushroom marketing and processing. At the same time, changes also led to the market concentration of open-market sales in large private enterprises and functional wholesalers. Main structure, organization and trends of the Mexican mushroom marketing system are discussed.

  9. Analogical reasoning for reliability analysis based on generic data

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, Igor O

    1996-10-01

    The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects.

  10. Analogy-Enhanced Instruction: Effects on Reasoning Skills in Science

    Science.gov (United States)

    Remigio, Krisette B.; Yangco, Rosanelia T.; Espinosa, Allen A.

    2014-01-01

    The study examined the reasoning skills of first year high school students after learning general science concepts through analogies. Two intact heterogeneous sections were randomly assigned to Analogy-Enhanced Instruction (AEI) group and Non Analogy-Enhanced (NAEI) group. Various analogies were incorporated in the lessons of the AEI group for…

  11. Analog Forecasting with Dynamics-Adapted Kernels

    CERN Document Server

    Zhao, Zhizhen

    2014-01-01

    Analog forecasting is a non-parametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from state-space reconstruction for dynamical systems and kernel methods developed in harmonic analysis and machine learning. The first improvement is to augment the dimension of the initial data using Takens' delay-coordinate maps to recover information in the initial data lost through partial observations. Then, instead of using Euclidean distances between the states, weighted ensembles of analogs are constructed according to similarity kernels in delay-coordinate space, featuring an explicit dependence on the dynamical vector field generating the data. The eigenvalues and eigenfunctions ...

  12. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  13. Analog pipeline readout for ATLAS calorimetry

    International Nuclear Information System (INIS)

    This paper presents the design and prototype testing of an analog pipeline readout module suitable for readout of the LAr calorimetry at the large hadron collider. The design has been driven by the readout requirements of the ATLAS electromagnetic liquid argon calorimeter and the ATLAS trigger design parameters. The results indicate that an analog pipeline readout system meeting the ATLAS requirements can be built using our modules. The SCA-chip employed has resolution approaching 13-bits (using the full range of the SCA) and can achieve a 16-bit dynamic range using a dual-range scheme. The module is based on switched capacitor array chips. A brief description of the design of the pipeline controller development, that will enable the SCA readout system to run as a deadtimeless analog RAM, is also given. (orig.)

  14. On Lovelock analogs of the Riemann tensor

    Energy Technology Data Exchange (ETDEWEB)

    Camanho, Xian O. [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik, Golm (Germany); Dadhich, Naresh [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); Inter-University Centre for Astronomy and Astrophysics, Pune (India)

    2016-03-15

    It is possible to define an analog of the Riemann tensor for Nth order Lovelock gravity, its characterizing property being that the trace of its Bianchi derivative yields the corresponding analog of the Einstein tensor. Interestingly there exist two parallel but distinct such analogs and the main purpose of this note is to reconcile both formulations. In addition we will introduce a simple tensor identity and use it to show that any pure Lovelock vacuum in odd d = 2N + 1 dimensions is Lovelock flat, i.e. any vacuum solution of the theory has vanishing Lovelock-Riemann tensor. Further, in the presence of cosmological constant it is the Lovelock-Weyl tensor that vanishes. (orig.)

  15. Biosynthesis of amphetamine analogs in plants.

    Science.gov (United States)

    Hagel, Jillian M; Krizevski, Raz; Marsolais, Frédéric; Lewinsohn, Efraim; Facchini, Peter J

    2012-07-01

    Amphetamine analogs are produced by plants in the genus Ephedra and by Catha edulis, and include the widely used decongestants and appetite suppressants pseudoephedrine and ephedrine. A combination of yeast (Candida utilis or Saccharomyces cerevisiae) fermentation and subsequent chemical modification is used for the commercial production of these compounds. The availability of certain plant biosynthetic genes would facilitate the engineering of yeast strains capable of de novo pseudoephedrine and ephedrine biosynthesis. Chemical synthesis has yielded amphetamine analogs with myriad functional group substitutions and diverse pharmacological properties. The isolation of enzymes with the serendipitous capacity to accept novel substrates could allow the production of substituted amphetamines in synthetic biosystems. Here, we review the biology, biochemistry and biotechnological potential of amphetamine analogs in plants. PMID:22502775

  16. Landauer Bound for Analog Computing Systems

    CERN Document Server

    Diamantini, M Cristina; Trugenberger, Carlo A

    2016-01-01

    By establishing a relation between information erasure and continuous phase transitions we generalise the Landauer bound to analog computing systems. The entropy production per degree of freedom during erasure of an analog variable (reset to standard value) is given by the logarithm of the configurational volume measured in units of its minimal quantum. As a consequence every computation has to be carried on with a finite number of bits and infinite precision is forbidden by the fundamental laws of physics, since it would require an infinite amount of energy.

  17. Doing mathematics convention, subject, calculation, analogy

    CERN Document Server

    Krieger, Martin H

    2003-01-01

    This book discusses some ways of doing mathematical work and the subject matter that is being worked upon and created. It argues that the conventions we adopt, the subject areas we delimit, what we can prove and calculate about the physical world, and the analogies that work for mathematicians - all depend on mathematics, what will work out and what won't. And the mathematics, as it is done, is shaped and supported, or not, by convention, subject matter, calculation, and analogy. The cases studied include the central limit theorem of statistics, the sound of the shape of a drum, the connection

  18. Space flight nutrition research: platforms and analogs

    Science.gov (United States)

    Smith, Scott M.; Uchakin, Peter N.; Tobin, Brian W.

    2002-01-01

    Conducting research during actual or simulated weightlessness is a challenging endeavor, where even the simplest activities may present significant challenges. This article reviews some of the potential obstacles associated with performing research during space flight and offers brief descriptions of current and previous space research platforms and ground-based analogs, including those for human, animal, and cell-based research. This review is intended to highlight the main issues of space flight research analogs and leave the specifics for each physiologic system for the other papers in this section.

  19. Associative Pattern Recognition In Analog VLSI Circuits

    Science.gov (United States)

    Tawel, Raoul

    1995-01-01

    Winner-take-all circuit selects best-match stored pattern. Prototype cascadable very-large-scale integrated (VLSI) circuit chips built and tested to demonstrate concept of electronic associative pattern recognition. Based on low-power, sub-threshold analog complementary oxide/semiconductor (CMOS) VLSI circuitry, each chip can store 128 sets (vectors) of 16 analog values (vector components), vectors representing known patterns as diverse as spectra, histograms, graphs, or brightnesses of pixels in images. Chips exploit parallel nature of vector quantization architecture to implement highly parallel processing in relatively simple computational cells. Through collective action, cells classify input pattern in fraction of microsecond while consuming power of few microwatts.

  20. One higher dimensional analog of jet schemes

    OpenAIRE

    Yuen, Cornelia

    2006-01-01

    We develop the theory of truncated wedge schemes, a higher dimensional analog of jet schemes. We prove some basic properties and give an irreducibility criterion for truncated wedge schemes of a locally complete intersection variety analogous to Musta\\c{t}\\v{a}'s for jet schemes. We show that the reduced subscheme structure of a truncated wedge scheme of any monomial scheme is itself a monomial scheme in a natural way by explicitly describing generators of each of the minimal primes of any tr...

  1. Discrete analog computing with rotor-routers.

    Science.gov (United States)

    Propp, James

    2010-09-01

    Rotor-routing is a procedure for routing tokens through a network that can implement certain kinds of computation. These computations are inherently asynchronous (the order in which tokens are routed makes no difference) and distributed (information is spread throughout the system). It is also possible to efficiently check that a computation has been carried out correctly in less time than the computation itself required, provided one has a certificate that can itself be computed by the rotor-router network. Rotor-router networks can be viewed as both discrete analogs of continuous linear systems and deterministic analogs of stochastic processes. PMID:20887076

  2. Analog circuit design for communication SOC

    CERN Document Server

    Tu, Steve Hung-Lung

    2012-01-01

    This e-book provides several state-of-the-art analog circuit design techniques. It presents both empirical and theoretical materials for system-on-a-chip (SOC) circuit design. Fundamental communication concepts are used to explain a variety of topics including data conversion (ADC, DAC, S-? oversampling data converters), clock data recovery, phase-locked loops for system timing synthesis, supply voltage regulation, power amplifier design, and mixer design. This is an excellent reference book for both circuit designers and researchers who are interested in the field of design of analog communic

  3. MEXICO Wants to Attract Chinese Tourists

    Institute of Scientific and Technical Information of China (English)

    Audrey GUO

    2009-01-01

    @@ Though last year many countries were affected by the global financial crisis,tourism in Mexico enjoyed an increase of 5% in 2008.Aiming at attracting more Chinese tourists to Mexico,on April 7,2009,Ambassador Jorge Guajardo together with Mr.Eligio Serna,China Director of the Mexico Tourism Board,held a conference to introduce Mexico Travel in Mexico Embassy to China,Beijing.

  4. Estimation of Seasonal Risk Caused by the Intake of Lead, Mercury and Cadmium through Freshwater Fish Consumption from Urban Water Reservoirs in Arid Areas of Northern Mexico

    Directory of Open Access Journals (Sweden)

    Myrna Nevárez

    2015-02-01

    Full Text Available Bioavailability and hence bioaccumulation of heavy metals in fish species depends on seasonal conditions causing different risks levels to human health during the lifetime. Mercury, cadmium and lead contents in fish from Chihuahua (Mexico water reservoirs have been investigated to assess contamination levels and safety for consumers. Muscle samples of fish were collected across the seasons. Lead and cadmium were analyzed by inductively coupled plasma-optical emission spectrometry, and mercury by cold-vapor atomic absorption spectrometry. The highest concentrations of cadmium (0.235 mg/kg, mercury (0.744 mg/kg and lead (4.298 mg/kg exceeded the maximum levels set by European regulations and Codex Alimentarius. Lead concentrations found in fish from three water reservoirs also surpassed the limit of 1 mg/kg established by Mexican regulations. The provisional tolerable weekly intake (PTWI suggested by the World Health Organization for methyl mercury (1.6 µg/kg bw per week was exceeded in the spring season (1.94 µg/kg bw per week. This might put consumers at risk of mercury poisoning.

  5. Risk factors associated with prevalence of antibodies to Leptospira interrogans in a metapopulation of black-tailed prairie dogs in Mexico.

    Science.gov (United States)

    Montiel-Arteaga, Ana; Atilano, Daniel; Ayanegui, Alejandra; Ceballos, Gerardo; Suzán, Gerardo

    2015-01-01

    Interest in the study of infectious diseases of wildlife has grown in recent decades and now focuses on understanding host-parasite dynamics and factors involved in disease occurrence. The black-tailed prairie dog (Cynomys ludovicianus) is a useful species for this type of investigation because it lives in heterogeneous landscapes where human activities take place, and its populations are structured as a metapopulation. Our goal was to determine if colony area, density, and proximity to human settlements are associated with prevalence of antibodies to Leptospira interrogans in black-tailed prairie dogs of northwestern Chihuahua State, Mexico. We captured 266 prairie dogs in 11 colonies in 2009 and analyzed 248 serum samples with the microscopic agglutination test (MAT) for antibody to any of the 12 pathogenic serovars of L. interrogans. Serologically positive test results for only serovars Bratislava, Canicola, Celledoni, and Tarassovi were considered for statistical analysis. Almost 80% of sera were positive for at least one pathogenic serovar (MAT titer ≥1∶80). The highest recorded antibody prevalences were to serovars Bratislava and Canicola. Correlation analysis showed a negative relationship between L. interrogans antibody prevalence and colony area (r = -0.125, Pleptospirosis in threatened wildlife species. Further studies are needed to evaluate the impact of Leptospira serovars in metapopulations of prairie dogs and other domestic and wild mammals in grassland communities. PMID:25380365

  6. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    NARCIS (Netherlands)

    van de Plassche, R.J.

    1989-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog filte

  7. Polymorphism of locus DRB3.2 in populations of Creole Cattle from Northern Mexico

    Directory of Open Access Journals (Sweden)

    Ilda G. Fernández

    2008-01-01

    Full Text Available The polymorphism of locus BoLA-DRB3.2 of the Major Histocompatibility Complex was evaluated in two northern Mexican Creole cattle populations, Chihuahua (n = 47 and Tamaulipas (n = 51. The BoLA-DRB3.2 locus was typed by amplification and digestion with restriction endonuclease enzymes (PCR-RFLP. Fifty-two alleles were detected (28 previously reported and 24 new ones. In the Chihuahua population, 18 alleles and 5.5 effective alleles were found, while in the Tamaulipas population there were 34 and 10.8, respectively. The allele frequencies ranged from 0.011 to 0.383 in Chihuahua and from 0.010 to 0.206 in Tamaulipas. The frequencies of the new alleles in both cattle populations were low (0.010 to 0.053. The expected heterozygosity was 0.827 and 0.916, respectively, for the Chihuahua and Tamaulipas populations. Both populations presented a heterozygote deficit: [Chihuahua F IS = 0.1 (p = 0.019 and Tamaulipas F IS = 0.317 (p < 0.001]. In conclusion, this study showed that the Mexican Creole cattle have many low-frequency alleles, several of which are exclusive to these populations. Genetic distances obtained show that the Mexican Creole cattle population is composed of independent populations, far apart from other South American Creole populations.

  8. Surgical education in Mexico.

    Science.gov (United States)

    Cervantes, Jorge

    2010-05-01

    Surgical education in Mexico basically follows the same model as in the United States, with a selection process resembling the matching program. There is a 4-year training period during which residents in their third year spend 4 months as the sole surgeon in a rural community. During the senior year they are entitled to an elective period in a place of their choosing. After completion of the 4 years, residents have to present a thesis and undergo an oral examination before getting a university diploma. They are then encouraged to pass the written and oral examination of the Mexican Board of Surgery before they are fully certified to enter practice in a public or private hospital. PMID:19603225

  9. The GMO-Nanotech (Dis)Analogy?

    Science.gov (United States)

    Sandler, Ronald; Kay, W. D.

    2006-01-01

    The genetically-modified-organism (GMO) experience has been prominent in motivating science, industry, and regulatory communities to address the social and ethical dimensions of nanotechnology. However, there are some significant problems with the GMO-nanotech analogy. First, it overstates the likelihood of a GMO-like backlash against…

  10. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  11. A high-speed analog neural processor

    NARCIS (Netherlands)

    Masa, Peter; Hoen, Klaas; Wallinga, Hans

    1994-01-01

    Targeted at high-energy physics research applications, our special-purpose analog neural processor can classify up to 70 dimensional vectors within 50 nanoseconds. The decision-making process of the implemented feedforward neural network enables this type of computation to tolerate weight discretiza

  12. Analog Optical Computing Primitives in Silicon Photonics

    CERN Document Server

    Jiang, Yunshan; Jalali, Bahram

    2015-01-01

    Optical computing accelerators may help alleviate bandwidth and power consumption bottlenecks in electronics. We show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

  13. Analog optical computing primitives in silicon photonics

    Science.gov (United States)

    Jiang, Yunshan; DeVore, Peter T. S.; Jalali, Bahram

    2016-03-01

    Optical computing accelerators may help alleviate bandwidth and power consumption bottlenecks in electronics. We show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

  14. Biological Analogs for Language Contact Situations

    Science.gov (United States)

    Seliger, Herbert W.

    1977-01-01

    This article proposes that language contact can be best understood if the entire range of such situations from second language learning to evolution of dialects and creoles is studied within a framework analogical to the symbiosis of living organisms. Language contact is viewed in terms of dynamic evolutionary stages. (CHK)

  15. A Mechanical Analogy for Ohm's Law.

    Science.gov (United States)

    do Couto Tavares, Milton; And Others

    1991-01-01

    A mechanical analogy between the microscopic motion of a charged carrier in an ordinary resistor and the macroscopic motion of a ball falling along a slanted board covered with a lattice of nails is introduced. The Drude model is also introduced to include the case of inelastic collisions. Computer simulation of the motion is described. (KR)

  16. Formal analogies in physics teacher education

    DEFF Research Database (Denmark)

    Avelar Sotomaior Karam, Ricardo; Ricardo, Elio

    2012-01-01

    . Despite the relevance of the subject, formal analogies are rarely systematically approached in physics education. In order to discuss this issue with pre-service physics teachers, we planned a lecture and designed a questionnaire with the goal of encouraging them to think about some “coincidences” in well...

  17. Plasma analog of particle-pair production

    International Nuclear Information System (INIS)

    It is shown that the plasma axial shear flow instability satisfies the Klein-Gordon equation. The plasma instability is then shown to be analogous to spontaneous particle-pair production when a potential energy is present that is greater than twice the particle rest mass energy. Stability criteria can be inferred based on field theoretical conservation laws. (UK)

  18. Radiation Behavior of Analog Neural Network Chip

    Science.gov (United States)

    Langenbacher, H.; Zee, F.; Daud, T.; Thakoor, A.

    1996-01-01

    A neural network experiment conducted for the Space Technology Research Vehicle (STRV-1) 1-b launched in June 1994. Identical sets of analog feed-forward neural network chips was used to study and compare the effects of space and ground radiation on the chips. Three failure mechanisms are noted.

  19. Bootstrapped Low-Voltage Analog Switches

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1999-01-01

    Novel low-voltage constant-impedance analog switch circuits are proposed. The switch element is a single MOSFET, and constant-impedance operation is obtained using simple circuits to adjust the gate and bulk voltages relative to the switched signal. Low-voltage (1-volt) operation is made feasible...

  20. A study about the possible mining and benefit of the uranium ores of the ''Las Margaritas'' deposit, in Sierra de Pena Blanca, municipality of Villa Aldama, State of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Considering all the characteristics of the deposit as well as its location in relation to the others, the necessary personnel, the extraction yield the structural conditions, etc. we can say that an advisable method of exploitation is the open pit method because in that way we can resolve a great number of problems, principally the high radiation to which the personnel would be exposed in a subterraneous work. The deposit reserves are 1,221,868 tons of ore with an average of 880 grams of U3O8 per ton. During the exploitation at open pit 1,147,025 tons will be extracted and through subterraneous work other 50,406 tons will be recuperated. The exploitation will cost $84.00 Mexican currency per ton. According to the experimental studies about the mineral which will be treated it has been concluded that the conventional acid leaching is the appropriate treatment to be followed since the recoveries were of 88 to 95%. However, it is suggested to make more studies about the metallurgical aspect and industrial engineering studies in order to lower costs, since these are theoretical and can be improved in the practice. (author)

  1. New Mexico Urban Areas - Current

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The TIGER/Line Shapefiles are an extract of selected geographic and cartographic information from the Census MAF/TIGER database. The Census MAF/TIGER database...

  2. New Mexico, 2010 Census Place

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and cartographic information from the U.S. Census...

  3. MARKETING WINTER VEGETABLES FROM MEXICO

    OpenAIRE

    Calvin, Linda; Barrios, Veronica

    1999-01-01

    The North American winter-vegetable industry is highly integrated, with Mexican production supplying a large part of U.S. winter consumption needs. Imports from Mexico undergo a rigorous inspection procedure before entering the United States. In addition to Mexican firms, many U.S. firms are also involved in sourcing winter vegetables from Mexico. To compete well, both U.S. and Mexican firms must adapt to the changing market pressures, which reward firms that can source from many locations to...

  4. Transportation energy use in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum, C.; Meyers, S.; Sathaye, J.

    1994-07-01

    This report presents data on passenger travel and freight transport and analysis of the consequent energy use in Mexico during the 1970--1971 period. We describe changes in modal shares for passenger travel and freight transport, and analyze trends in the energy intensity of different modes. We look in more detail at transportation patterns, energy use, and the related environmental problems in the Mexico City Metropolitan Area, and also discuss policies that have been implemented there to reduce emissions from vehicles.

  5. Oil and Gas in Mexico

    OpenAIRE

    Víctor Gerardo Carreón Rodríguez; Juan Rosellón

    2012-01-01

    Mexico is a highly centralized federation. The states and municipalities are highly dependent on federal transfers and so equally at risk to the country’s fiscal dependence on oil. Although Mexico has become more truly federal since multiparty competition has become vibrant and several states are in opposition hands, the states remain very minor actors in relation to oil and gas. However, as the political system has democratized, states have had an increasing say regarding oil and gas activit...

  6. NAFTA and Mexico's Economic Performance

    OpenAIRE

    Tornell, Aaron; Westermann, Frank; Martínez, Lorenza

    2004-01-01

    Mexico, a prominent liberalizer, failed to attain stellar gross domestic product (GDP) growth in the 1990s, and since 2001 its GDP and exports have stagnated. In this paper we argue that the lack of spectacular growth in Mexico cannot be blamed on either the North American Free Trade Agreement (NAFTA) or the other reforms that were implemented, but on the lack of further judicial and structural reform after 1995. In fact, the benefits of liberalization can be seen in the extraordinary growth ...

  7. Study of radioactive contamination in silts and aerosols at Aldama City, Mexico, due to the operation of a yellow-cake processing plant.

    Science.gov (United States)

    Montelongo, Michel Y; Herrera, Eduardo F; Ramirez, Elias; Carrillo, Jorge I; Campos, Alfredo; Gomez, Ramón; Montero, Maria E; Rodriguez, Luis M

    2015-08-01

    The city of Aldama, Chihuahua, Mexico is located 30 km NNE of Chihuahua city. Three high-volume collectors with PM10 heads were placed in specific locations in Aldama during the year 2011 to measure radioisotope concentrations in the air. The city area of 16 km² was divided into 64 squares of 500 × 500 m. At the vertices of the grid, silt samples were taken between January and June 2011, before the rains began. The concentrations of natural, cosmogenic, and anthropogenic radioactive isotopes were calculated in both filters and silts samples. The isotopes selected for the measurement were ²³⁸U, ²³²Th, (7)Be, ¹³⁷Cs, and ⁴⁰K. Measurements of PM10 and silts were performed during 2011, coinciding with the accident at Fukushima, Japan, on March 11. For this reason, we could see the ¹³⁷Cs in PM10 increase between April and July; with the arrival of the rains, the ¹³⁷Cs concentration began to decrease in the air. The concentration of PM10 measured by the equipment located at the Mexican Uranium plant (URAMEX, initials in Spanish) that was processing radioactive ores exceeded the standard values in February and March, when the air velocity increases. At City Hall, the concentration of PM10 surpassed the value of the standard between May and July. This increased concentration is likely due to increased automobile traffic because City Hall is located in the city center. At a private home, the concentration of PM10 surpassed the standard on several days during the year because the home is located on the outskirts of the city, where most of the streets are not paved. Due to the high concentrations of PM10, especially at the collection point located at the private home, it is necessary to start taking steps to mitigate their spread before they cause health problems in the younger population and in older adults. PMID:26211631

  8. Deficiencia de folatos y su asociación con defectos de cierre del tubo neural en el norte de México Folic acid deficiency and its relationship with neural tube defects in northern Mexico

    Directory of Open Access Journals (Sweden)

    Martha Rodríguez-Morán

    1998-11-01

    Full Text Available Objetivo. Valorar la asociación de la deficiencia de folatos y otros factores de riesgo con la ocurrencia de defectos de cierre del tubo neural (DCTN, en la población rural del norte de México (Chihuahua, Durango y Zacatecas. Material y métodos. Se hizo un estudio multicéntrico de casos y controles. Se consideraron como casos a los recién nacidos vivos (RNV y a los muertos con DCTN, y como controles, a los RNV sanos, no malformados. Se determinó la exposición a factores de riesgo conocidos, estableciendo su asociación con los DCTN, con un modelo de análisis múltiple de regresión logística. Resultados. Los factores de riesgo asociados a DCTN fueron: la deficiencia de folatos (RM 11.1; IC95% 1.2-106.2, p= 0.04; el antecedente, en embarazos previos, de productos con DCTN (RM 3.3; IC95% 1.1-18.8, p= 0.05, y óbitos (RM 7.1; IC95% 1.1-46.3, p= 0.04. Conclusiones. La deficiencia de folatos constituye uno de los principales factores de riesgo asociado a los DCTN en la población rural del norte de México. Es necesario llevar a cabo más investigaciones para determinar la contribución de otros factores de riesgo y establecer las medidas preventivas adecuadas.Objective. To evaluate folic acid deficiency and other risk factors and their relationship with the occurrence of neural tube defects (NTD, in the rural population of northern Mexico (Chihuahua, Durango and Zacatecas. Material and methods. A multicentric case-control study was performed. Cases were both live and stillborn with NTD, and controls were healthy newborns without congenital malformations. Exposure to known risk factors was determined, establishing its association with NTD using multiple logistic regression analysis. Results. Risk factors associated to NTD were: folic acid deficiency (OR 11.1; CI 95% 1.2-106.2, p= 0.04; the antecedents of previous NTD pregnancies (OR 3.3; CI 95% 1.1-18.8, p= 0.05 and stillbirths (OR 7.1; CI 95% 1.1-46.3, p= 0.04. Conclusions. Folic acid

  9. Resources of thermal control in vernacular houses of North of Mexico and Peru. A comparative analysis; Recursos de control termico en viviendas vernaculas del Norte de Mexico y Peru. Un analisis comparativo

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, Luis F. [Universidad Autonoma Metropolitana Azcapotzalco, Mexico, D.F.(Mexico)

    2000-07-01

    In this paper results of a comparative analysis made between prehispanic houses and vernacular houses at the environs of the city of Trujillo, Peru and of Casas Grandes in Chihuahua, Mexico, are presented, with the purpose of identifying the formal, functional and material characteristics that allowed their thermal adaptation to geographic environments with hostile climates, resulting from their location in desert zones. Without having existed any contact between the historical and vernacular cultures that were developed almost two thousand years ago in the Valley of Moche and the Valley of Casas Grandes, a series of architectonic answers with remarkable coincidences has been generated in their effectiveness to be integrated to the extreme prevailing climatic conditions. Among these answers it is possible to emphasize the use of soil as construction material, the structure massiveness, geographic orientation, roof slopes, dimensions of their premises, grouping forms, window types, open spaces, sunshades, rooftop gardens and lattice windows, among other design resources. Nevertheless, with the passage of time an important part of the knowledge that based these forms of adaptation to the environment were being lost and the architecture transformed to give way to a vernacular tradition whose characteristics have turned out to be less and less efficient. Most serious of this tendency is that in recent years, as a result of the incorporation of other people's construction systems, the local architecture has been degenerating until almost totally loose the traits that supported their integration to the surrounding environment transforming itself into spaces with a null thermal comfort. The analysis not only allows to evaluate the architectonic elements identified to promote their conservation as an historical testimony but fundamentally, as a source for designing housing solutions that at present and in the future will recover the ancestral wisdom. [Spanish] En esta

  10. Governability in Contemporary Mexico

    Directory of Open Access Journals (Sweden)

    Leonardo Curzio Gutiérrez

    1998-04-01

    Full Text Available Given the difficulties to establish a concept of governability and the frequent ideological usage of the term, it is much more operative to turn to the principle of governability, in the broad sense, which supports itself on five pillars: the political legitimacy of the government, the governmental efficiency to attend to the demands of society, the existence of shared social project, the agreement with the principle special interest groups, and international viability. The analysis of the structure and relevance of these five points during the long period of political transition that Mexico underwent between 1988 and 1997 shows how it was possible for this country to play off certain factors against each other in order to secure governability and safeguard against the consequences of any resultant imbalances. Between 1998-1993, the government of Salinas de Gotari based itself on the viability of a neoliberal project within an international context, and on this projectís attention to domestic demands as well as on the governmentís pact with elites. Institutional integration and legitimacy made up, then, for a process of discreet liberalization and the lack of democratic electoral commitment, which culminated in the PRI’s 1994 elections victory.The assassination of Colosia, though, and the appearance of the EZLN and the subsequent crisis surrounding the peso’s devaluation that accompanied Ernesto Zedilloís rise to power soon led to the collapse of those pillars of support. Crowning the process of the silenttransition were the elections of 1997, which makes it possible to say that in Mexico today there are now smooth elections, but that reform of the State is still unresolved —a subject that includes the reduction of the president’s competence. Seen in the short term, the most direct threats to Mexico’s governability will come as a result of the lack of attention to those demands of society’s underprivileged and the ill

  11. Analog Computation by DNA Strand Displacement Circuits.

    Science.gov (United States)

    Song, Tianqi; Garg, Sudhanshu; Mokhtar, Reem; Bui, Hieu; Reif, John

    2016-08-19

    DNA circuits have been widely used to develop biological computing devices because of their high programmability and versatility. Here, we propose an architecture for the systematic construction of DNA circuits for analog computation based on DNA strand displacement. The elementary gates in our architecture include addition, subtraction, and multiplication gates. The input and output of these gates are analog, which means that they are directly represented by the concentrations of the input and output DNA strands, respectively, without requiring a threshold for converting to Boolean signals. We provide detailed domain designs and kinetic simulations of the gates to demonstrate their expected performance. On the basis of these gates, we describe how DNA circuits to compute polynomial functions of inputs can be built. Using Taylor Series and Newton Iteration methods, functions beyond the scope of polynomials can also be computed by DNA circuits built upon our architecture. PMID:27363950

  12. Optimal neural computations require analog processors

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.

    1998-12-31

    This paper discusses some of the limitations of hardware implementations of neural networks. The authors start by presenting neural structures and their biological inspirations, while mentioning the simplifications leading to artificial neural networks. Further, the focus will be on hardware imposed constraints. They will present recent results for three different alternatives of parallel implementations of neural networks: digital circuits, threshold gate circuits, and analog circuits. The area and the delay will be related to the neurons` fan-in and to the precision of their synaptic weights. The main conclusion is that hardware-efficient solutions require analog computations, and suggests the following two alternatives: (i) cope with the limitations imposed by silicon, by speeding up the computation of the elementary silicon neurons; (2) investigate solutions which would allow the use of the third dimension (e.g. using optical interconnections).

  13. ON THE FREQUENCY OF JUPITER ANALOGS

    International Nuclear Information System (INIS)

    The Anglo-Australian Planet Search has now accumulated 12 years of radial-velocity data with long-term instrumental precision better than 3 m s-1. In this paper, we expand on earlier simulation work, to probe the frequency of near-circular, long-period gas-giant planets residing at orbital distances of 3-6 AU-the so-called Jupiter analogs. We present the first comprehensive analysis of the frequency of these objects based on radial-velocity data. We find that 3.3% of stars in our sample host Jupiter analogs; detailed, star-by-star simulations show that no more than 37% of stars host a giant planet between 3 and 6 AU.

  14. Observing spin optodynamical analog of cavity optomechanics

    Science.gov (United States)

    Gerber, Justin; Kohler, Jonathan; Spethmann, Nicolas; Schreppler, Sydney; Stamper-Kurn, Dan

    2016-05-01

    Cavity Optomechanics has been realized in many diverse systems and led to many interesting results such as ponderomotive squeezing of light, beyond-SQL measurement sensitivity, and squeezing of mechanical oscillators. Optical cavities also allow sensitive measurements of the spin of an atomic ensemble. It has been proposed to utilize this sensitivity to realize an analog of optomechanics by measuring the precession of small excitations of a spin-oscillator around a transverse magnetic field. I will present our recent work in which we realize optomechanical analogs in our system such as cavity-assisted cooling and amplification and optical spring shifts. In addition, the presence of a high-energy `ground state' of the spin oscillator allows the realization of an effective negative mass oscillator which is demonstrated by an inverted sideband asymmetry. In our ongoing work we attempt to realize coherent quantum noise cancelation by coupling spin oscillation with mechanical oscillation.

  15. High resolution tomography using analog coding

    International Nuclear Information System (INIS)

    As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

  16. An analogy strategy for transformation optics

    International Nuclear Information System (INIS)

    We introduce an analogy strategy to design transformation optical devices. Based on the similarities between field lines in different physical systems, the trajectories of light can be intuitively determined to curve in a gentle manner, and the resulting materials are isotropic and nonmagnetic. Furthermore, the physical meaning of the analogue problems plays a key role in the removal of dielectric singularities. We illustrate this approach by creating two designs of carpet cloak and a collimating lens as representative examples in two- and three-dimensional spaces, respectively. The analogy strategy not only reveals the intimate connections between different physical disciplines, such as optics, fluid mechanics and electrostatics, but also provides a heuristic pathway to designing advanced photonic systems

  17. Analog data transmission via fiber optics

    International Nuclear Information System (INIS)

    In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particulary susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

  18. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum...... and minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test program. Patch instructions are printed by HAPS. The article describes the principles of HAPS...... and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing....

  19. Analog fault diagnosis by inverse problem technique

    KAUST Repository

    Ahmed, Rania F.

    2011-12-01

    A novel algorithm for detecting soft faults in linear analog circuits based on the inverse problem concept is proposed. The proposed approach utilizes optimization techniques with the aid of sensitivity analysis. The main contribution of this work is to apply the inverse problem technique to estimate the actual parameter values of the tested circuit and so, to detect and diagnose single fault in analog circuits. The validation of the algorithm is illustrated through applying it to Sallen-Key second order band pass filter and the results show that the detecting percentage efficiency was 100% and also, the maximum error percentage of estimating the parameter values is 0.7%. This technique can be applied to any other linear circuit and it also can be extended to be applied to non-linear circuits. © 2011 IEEE.

  20. Electromagnetotoroid Structures and their Hydrodynamic Analogs

    CERN Document Server

    Pinheiro, Mario J

    2012-01-01

    We introduce the concept of an electromagnetotoroid in astrophysics, and explore its role in polar jets. This model represents the onset of Abraham's force driven by some external source, for example, the infall of gas towards a star. The Abraham's force term is analogous to the Magnus force, and thus represents the formation of electromagnetic vortex structures in the fabric of space-time. In principle, the proposed toroidal field structure can also provide force spaceship propulsion.

  1. Interference Alignment with Analog Channel State Feedback

    OpenAIRE

    Ayach, Omar El; Heath Jr, Robert W.

    2010-01-01

    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel. While the achieved sum rate with IA is much higher than previously thought possible, the improvement often comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet potentially costly approach that incurs large overhead. In this paper we propose analog feedback as an alternative to limited feedback ...

  2. Pyrrolidine nucleotide analogs with a tunable conformation

    Czech Academy of Sciences Publication Activity Database

    Poštová Slavětínská, Lenka; Rejman, Dominik; Pohl, Radek

    2014-01-01

    Roč. 10, Aug 22 (2014), s. 1967-1980. ISSN 1860-5397 R&D Projects: GA ČR GA13-24880S Institutional support: RVO:61388963 Keywords : conformation * NMR * nucleic acids * nucleotide analog * phosphonic acid * pseudorotation * pyrrolidine Subject RIV: CC - Organic Chemistry Impact factor: 2.762, year: 2014 http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?publicId=1860-5397-10-205

  3. Quantum Electric Circuits Analogous to Ballistic Conductors

    OpenAIRE

    Dragoman, Daniela

    2007-01-01

    The conductance steps in a constricted two-dimensional electron gas and the minimum conductivity in graphene are related to a new uncertainty relation between electric charge and conductance in a quantized electric circuit that mimics the electric transport in mesoscopic systems. This uncertainty relation makes specific use of the discreteness of electric charge. Quantum electric circuits analogous to both constricted two-dimensional electron gas and graphene are introduced. In the latter cas...

  4. The 2012 Moon and Mars Analog Mission

    Science.gov (United States)

    Graham, Lee

    2014-01-01

    The 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were completed on Mauna Kea volcano in Hawaii in July 2012. The investigations were conducted on the southeast flank of the Mauna Kea volcano at an elevation of approximately 11,500 ft. This area is known as "Apollo Valley" and is in an adjacent valley to the Very Large Baseline Array dish antenna.

  5. SOI design analog, memory and digital techniques

    CERN Document Server

    Marshall, Andrew

    2007-01-01

    Preface. Acknowledgements. 1. Overview. 2. SOI Materials. 3. Components. 4. SOI Modeling. 5. Layout for SOI. 6. Static SOI Design. 7. Dynamic SOI Design. 8. SOI SRAMs. 9. SOI DRAMs. 10. SOI Analog Design. 11. Global Design Issues. 12. Low Power Design. 13. SOI in Development. Appendix 1: Internet Sites (issue 1.0). Appendix 2: Trade Mark / Technology Information (issue 1.0). Index. About the Authors.

  6. Developing Fluorescent Hyaluronan Analogs for Hyaluronan Studies

    OpenAIRE

    Shi Ke; Arlin G. Cameron; Wei Wang

    2012-01-01

    Two kinds of fluorescent hyaluronan (HA) analogs, one serving as normal imaging agent and the other used as a biosensitive contrast agent, were developed for the investigation of HA uptake and degradation. Our approach of developing HA imaging agents depends on labeling HA with varying molar percentages of a near-infrared (NIR) dye. At low labeling ratios, the hyaluronan uptake can be directly imaged while at high labeling ratios, the fluorescent signal is quenched and signal generation occur...

  7. Survey of Evaluated Isobaric Analog States

    Energy Technology Data Exchange (ETDEWEB)

    MacCormick, M., E-mail: maccorm@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS/IN2P3, Université Paris-Sud, 91406 Orsay CEDEX (France); Audi, G. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CNRS/IN2P3, Université Paris-Sud, Bât. 108, F-91405 Orsay Campus (France)

    2014-06-15

    Isobaric analog states (IAS) can be used to estimate the masses of members belonging to the same isospin multiplet. Experimental and estimated IAS have been used frequently within the Atomic Mass Evaluation (AME) in the past, but the associated set of evaluated masses have been published for the first time in AME2012 and NUBASE2012. In this paper the current trends of the isobaric multiplet mass equation (IMME) coefficients are shown. The T = 2 multiplet is used as a detailed illustration.

  8. OpenModelica for Analog IC Design

    OpenAIRE

    Malo Cid, David

    2011-01-01

    Modelica is a language supported by Modelica Association. It is a non-proprietary, object-oriented, equation based language to conveniently model complex physical. OpenModelica is an open source environment for the Modelica language supported by Open Source Modelica Consortium (OSMC). The aim of this thesis is the development of a library of models and components for design and simulation of analog integrated circuits and an OMNotebook-based tutorial for an academic purpose as a design tool f...

  9. The exoplanets analogy to the Multiverse

    OpenAIRE

    Kinouchi, Osame

    2015-01-01

    The idea of a Mutiverse is controversial, although it is a natural possible solution to particle physics and cosmological fine-tuning problems (FTPs). Here I explore the analogy between the Multiverse proposal and the proposal that there exist an infinite number of stellar systems with planets in a flat Universe, the Multiplanetverse. Although the measure problem is present in this scenario, the idea of a Multiplanetverse has predictive power, even in the absence of direct evidence for exopla...

  10. Biomedical sensor design using analog compressed sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

  11. Synthesis and Biological Evaluation of Paclitaxel Analogs

    OpenAIRE

    Baloglu, Erkan

    2001-01-01

    The complex natural product paclitaxel (Taxol®), first isolated from Taxus brevifolia, is a member of a large family of taxane diterpenoids. Paclitaxel is extensively used for the treatment of solid tumors, particularly those of the breasts and ovaries. In order to obtain additional information about the mechanism of action of paclitaxel and the environment of the paclitaxel-binding site, several fluorescent analogs of paclitaxel were synthesized, and thei...

  12. An introduction to analog and digital communications

    CERN Document Server

    Haykin, Simon

    2012-01-01

    The second edition of this accessible book provides readers with an introductory treatment of communication theory as applied to the transmission of information-bearing signals. While it covers analog communications, the emphasis is placed on digital technology. It begins by presenting the functional blocks that constitute the transmitter and receiver of a communication system. Readers will next learn about electrical noise and then progress to multiplexing and multiple access techniques.

  13. Controller implementation using analog reconfigurable hardware (FPAA)

    OpenAIRE

    Fonseca, Paulo Jorge Rodrigues da

    2015-01-01

    This Thesis has the main target to make a research about FPAA/dpASPs devices and technologies applied to control systems. These devices provide easy way to emulate analog circuits that can be reconfigurable by programming tools from manufactures and in case of dpASPs are able to be dynamically reconfigurable on the fly. It is described different kinds of technologies commercially available and also academic projects from researcher groups. These technologies are very recent and...

  14. Difficulties in constructing Bose analogs to supergravity

    International Nuclear Information System (INIS)

    An alternative to the usual fermionic supersymmetry transformations is discussed, namely bosonic ones in which the particle helicities are changed by an integral multiple of h/2π. No matter how such transformations are carried out, it appears that the road to a local supersymmtric analog to supergravity is closed, either because no gauge field of the required rank to couple with the supercurrent exists, or because the non-interacting action is already locally invariant, and hence the supercurrent vanishes identically. (Auth.)

  15. Priming Analogical Reasoning with False Memories

    OpenAIRE

    Howe, M. L.; Garner, S. R.; Threadgold, E.; Ball, L. J.

    2015-01-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false mem...

  16. Analog "neuronal" networks in early vision

    OpenAIRE

    Koch, C; Marroquin, J; Yuille, A.

    1986-01-01

    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be "solved" by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the...

  17. Analog controllers using digital stochastic logic

    OpenAIRE

    Quero Reboul, José Manuel; S. L. Toral; García Ortega, Juan de la Cruz; García Franquelo, Leopoldo

    1999-01-01

    Stochastic logic is based on digital processing of a random pulse stream, where the information is codified as the probability of a high level in a finite sequence. The probability of the pulse stream codifies a continuous time variable. Subsequently, this pulse stream can be digitally processed to perform analog operations. In this paper we propose a stochastic approach to the digital implementation of complex controllers. This is approach allows for the realization of the controllers, and A...

  18. Analog gravity from field theory normal modes?

    OpenAIRE

    Barcelo, Carlos; Liberati, Stefano; Visser, Matt

    2001-01-01

    We demonstrate that the emergence of a curved spacetime ``effective Lorentzian geometry'' is a common and generic result of linearizing a field theory around some non-trivial background. This investigation is motivated by considering the large number of ``analog models'' of general relativity that have recently been developed based on condensed matter physics, and asking whether there is something more fundamental going on. Indeed, linearization of a classical field theory (a field theoretic ...

  19. [Health manpower in Mexico].

    Science.gov (United States)

    Martuscelli, J

    1986-01-01

    Population increase, rural-to-urban migration, excessive population concentration side by side with scattered rural populations, and the economic crisis provide the primary framework for this analysis of health manpower in Mexico. The secondary frame of reference is the primary causes of mortality (in 1981): the leading cause, accidents and violence; the second, heart disease; the third, influenza and pneumonia; and the fourth, enteric diseases and diarrheas. Data are supplied on the number of new physicians graduating (this number rose from 2,493 in 1976 to 14,099 in 1983), and on the number of nurses (about 98,000, of which 40% are professionals). The growth pattern of the contingent of dentists is the same as that of physicians, namely, disproportionate and inefficient. The Federal Government is now trying to set up a National Health System that will fulfill the constitutional right of all Mexican citizens to health protection. On the basis of the disequilibrium apparent in every part of the health sector, the author recommends that educational and health institutions plan and coordinate the training of physicians so that the number of graduates may meet the country's needs, and the quality of their education may be improved. PMID:3780502

  20. Backtracking quantum trajectories with analog feedback

    Science.gov (United States)

    de Lange*, G.; Ristè*, D.; Tiggelman, M. J.; Eichler, C.; Tornberg, L.; Johansson, G.; Wallraff, A.; Schouten, R. N.; Dicarlo, L.

    2014-03-01

    Circuit quantum electrodynamics offers a nearly ideal platform for the fundamental study of continuous quantum measurement. A nondemolition measurement of a superconducting qubit can be performed via homodyne detection of microwave transmission through a dispersively coupled cavity. By boosting the homodyne signal with a nearly noiseless phase-sensitive parametric amplifier, we experimentally show that a form of measurement backaction, consisting of stochastic quantum phase kicks on the measured qubit, is highly correlated with the fluctuations in the continuous homodyne record. We demonstrate a real-time analog feedback scheme that counteracts these phase kicks and thereby reduces measurement-induced dephasing. We develop a numerical optimization technique to overcome the bandwidth limitations of the amplification chain and provide a theoretical model for the optimization result. A quantum efficiency of 50% is extracted for the complete analog feedback loop. Finally, we discuss the integration of this analog feedback technique to improve performance in our recent demonstration of entanglement by dispersive parity measurement. *equal contribution. Research funded by NWO and the EU projects SOLID and SCALEQIT.