1,691 research outputs found

    Neutrino mixing and masses in a left-right model with mirror fermions

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    In the framework of a left-right model containing mirror fermions with gauge group SU(3)CSU(2)LSU(2)RU(1)Y_{C} \otimes SU(2)_{L} \otimes SU(2)_{R} \otimes U(1)_{Y^\prime}, we estimate the neutrino masses, which are found to be consistent with their experimental bounds and hierarchy. We evaluate the decay rates of the Lepton Flavor Violation (LFV) processes μeγ\mu \rightarrow e \gamma, τμγ\tau \rightarrow \mu \gamma and τeγ\tau \rightarrow e\gamma. We obtain upper limits for the flavor-changing branching ratios in agreement with their present experimental bounds. We also estimate the decay rates of heavy Majorana neutrinos in the channels NW±lN \rightarrow W^{\pm} l^{\mp}, NZνlN \rightarrow Z \nu_{l} and NHνlN \rightarrow H \nu_{l}, which are roughly equal for large values of the heavy neutrino mass. Starting from the most general Majorana neutrino mass matrix, the smallness of active neutrino masses turns out from the interplay of the hierarchy of the involved scales and the double application of seesaw mechanism. An appropriate parameterization on the structure of the neutrino mass matrix imposing a symmetric mixing of electron neutrino with muon and tau neutrinos leads to Tri-bimaximal mixing matrix for light neutrinos.Comment: Accepted by European Physical Journal

    Neutrino masses and mixing parameters in a left-right model with mirror fermions

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    In this work we consider a left-right model containing mirror fermions with gauge group SU(3)CSU(2)LSU(2)RU(1)Y_{C} \otimes SU(2)_{L} \otimes SU(2)_{R} \otimes U(1)_{Y^\prime}. The model has several free parameters which here we have calculated by using the recent values for the squared-neutrino mass differences. Lower bound for the mirror vacuum expectation value helped us to obtain crude estimations for some of these parameters. Also we estimate the order of magnitude of the masses of the standard and mirror neutrinos.Comment: 13 pages, version submitted to European Physical Journal

    Hydrochemistry of the Mocorito river coastal aquifer, Sinaloa, Mexico: water quality assessment for human consumption and agriculture suitability

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    Background. Groundwater is a vital source of water for domestic and agricultural activities and the water of the Mocorito River Coastal Aquifer (MORCA), located in the agricultural valley of Culiacan, Sinaloa, Mexico, is not an exception. Goals. To assess MORCA's groundwater quality for drinking and irrigation purposes and the geochemical processes affecting its composition. Methods. Twenty-two well samples were collected during the dry and rainy seasons. Physical and chemical parameters, major ions, drinking quality (WQI and PHASECH water quality index), and irrigation suitability Richards (1954) and Wilcox diagrams) were studied. Results. Total Dissolved Solid (TDS) ranged from 1688 - 8762 mg L-1 for the dry season and 89-10016 mg L-1 for the rainy season. From inland to the coastal zone, MORCA's groundwater was considered hard and very hard, with non-dominant hydrochemical facies in the dry season and calcium, magnesium and sodium (cationic), and bicarbonate and chloride (anionic) types, in the rainy season. US Salinity Staff and Wilcox diagrams revealed that MORCA's groundwater is not suitable for use in irrigation. Further, the geochemical processes controlling the chemical composition of MORCA were evaporation and weathering. Conclusions. According to the TDS and water quality index (WQI and PHASECH) classifying just 4.5 % and over 50 % of the samples, respectively, MORCA water can be considered suitable for human consumption; only the groundwater from site EE-1, in the rainy season, was considered suitable for human consumption. US Salinity staff and Wilcox diagrams indicate that almost 50% of MORCA's groundwater is not suitable for irrigation use. MORCA's groundwater composition is dominated by evaporation and weathering of minerals such as anorthite, illite, and kaolinite.Background. Groundwater is a vital source of water for domestic and agricultural activities and the water of the Mocorito River Coastal Aquifer (MORCA), located in the agricultural valley of Culiacan, Sinaloa, Mexico, is not an exception. Goals. To assess MORCA's groundwater quality for drinking and irrigation purposes and the geochemical processes affecting its composition. Methods. Twenty-two well samples were collected during the dry and rainy seasons. Physical and chemical parameters, major ions, drinking quality (WQI and PHASECH water quality index), and irrigation suitability Richards (1954) and Wilcox diagrams) were studied. Results. Total Dissolved Solid (TDS) ranged from 1688 - 8762 mg L-1 for the dry season and 89-10016 mg L-1 for the rainy season. From inland to the coastal zone, MORCA's groundwater was considered hard and very hard, with non-dominant hydrochemical facies in the dry season and calcium, magnesium and sodium (cationic), and bicarbonate and chloride (anionic) types, in the rainy season. US Salinity Staff and Wilcox diagrams revealed that MORCA's groundwater is not suitable for use in irrigation. Further, the geochemical processes controlling the chemical composition of MORCA were evaporation and weathering. Conclusions. According to the TDS and water quality index (WQI and PHASECH) classifying just 4.5 % and over 50 % of the samples, respectively, MORCA water can be considered suitable for human consumption; only the groundwater from site EE-1, in the rainy season, was considered suitable for human consumption. US Salinity staff and Wilcox diagrams indicate that almost 50% of MORCA's groundwater is not suitable for irrigation use. MORCA's groundwater composition is dominated by evaporation and weathering of minerals such as anorthite, illite, and kaolinite

    Modulated-laser source induction system for remote detection of infrared emissions of high explosives using laser-induced thermal emission

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    In a homeland security setting, the ability to detect explosives at a distance is a top security priority. Consequently, the development of remote, noncontact detection systems continues to represent a path forward. In this vein, a remote detection system for excitation of infrared emissions using a CO2 laser for generating laser-induced thermal emission (LITE) is a possible solution. However, a LITE system using a CO2 laser has certain limitations, such as the requirement of careful alignment, interference by the CO2 signal during detection, and the power density loss due to the increase of the laser image at the sample plane with the detection distance. A remote chopped-laser induction system for LITE detection using a CO2 laser source coupled to a focusing telescope was built to solve some of these limitations. Samples of fixed surface concentration (500 μg∕cm2) of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) were used for the remote detection experiments at distances ranging between 4 and 8 m. This system was capable of thermally exciting and capturing the thermal emissions (TEs) at different times in a cyclic manner by a Fourier transform infrared (FTIR) spectrometer coupled to a gold-coated reflection optics telescope (FTIR-GT). This was done using a wheel blocking the capture of TE by the FTIR-GT chopper while heating the sample with the CO2 laser. As the wheel moved, it blocked the CO2 laser and allowed the spectroscopic system to capture the TEs of RDX. Different periods (or frequencies) of wheel spin and FTIR-GT integration times were evaluated to find dependence with observation distance of the maximum intensity detection, minimum signal-to-noise ratio, CO2 laser spot size increase, and the induced temperature incremen

    Coupling Mars Ground and Orbital Views: Generate Viewsheds of Mastcam Images From the Curiosity Rover, Using ArcGIS® and Public Datasets

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    The Mastcam (Mast Camera) instrument onboard the NASA Curiosity rover provides an exclusive view of Mars: High‐resolution color images from Mastcam allow users to study Gale crater's geologic terrains along Curiosity's path. These ground observations complement the spatially broader views of Gale crater provided by spacecrafts from orbit. However, for a given Mastcam image, it can be challenging to locate the corresponding terrains on the orbital view. No method for locating Mastcam images onto orbital images had been made publicly available. The procedure presented here allows users to generate Mastcam image viewsheds, using ArcGIS® software, its built‐in Viewshed tool®, and public Mars datasets. This procedure locates onto Mars orbital view the terrains that are observed in a given Mastcam image. Because this procedure uses public datasets, it is applicable to available Mastcam images and to the future ones that will be acquired along the Curiosity rover's path. This procedure can be used by the public to assess scientific questions regarding Martian surface processes and geologic history. In addition, this procedure can be utilized as pedagogic GIS material by the Geosciences or Planetary Sciences communities, for enhancing students' skillsets in GIS and provide students with experience working with datasets from both orbiter and rover Mars missions

    Coupling Mars Ground and Orbital Views: Generate Viewsheds of Mastcam Images From the Curiosity Rover, Using ArcGIS® and Public Datasets

    Get PDF
    The Mastcam (Mast Camera) instrument onboard the NASA Curiosity rover provides an exclusive view of Mars: High‐resolution color images from Mastcam allow users to study Gale crater's geologic terrains along Curiosity's path. These ground observations complement the spatially broader views of Gale crater provided by spacecrafts from orbit. However, for a given Mastcam image, it can be challenging to locate the corresponding terrains on the orbital view. No method for locating Mastcam images onto orbital images had been made publicly available. The procedure presented here allows users to generate Mastcam image viewsheds, using ArcGIS® software, its built‐in Viewshed tool®, and public Mars datasets. This procedure locates onto Mars orbital view the terrains that are observed in a given Mastcam image. Because this procedure uses public datasets, it is applicable to available Mastcam images and to the future ones that will be acquired along the Curiosity rover's path. This procedure can be used by the public to assess scientific questions regarding Martian surface processes and geologic history. In addition, this procedure can be utilized as pedagogic GIS material by the Geosciences or Planetary Sciences communities, for enhancing students' skillsets in GIS and provide students with experience working with datasets from both orbiter and rover Mars missions

    On the components of the unstable set of isolated invariant sets

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    The aim of this note is to shed some light on the topological structure of the unstable set of an isolated invariant set K. We give a bound on the number of essential quasicomponents of the unstable set of K in terms of the homological Conley index of K. The proof relies on an explicit pairing between Čech homology classes and Alexander–Spanier cohomology classes that takes the form of an integral.Depto. de Álgebra, Geometría y TopologíaFac. de Ciencias MatemáticasTRUEMinisterio de Ciencia, Innovación y Universidadespu

    Analysis of the Relationship between Lifestyle and Coffee Consumption Habits, from the Myth Approach, in the Municipalities of Orizaba, Tehuipango, and Zongolica Veracruz.

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    Coffee consumption habits have evolved along with society for more than 300 years around the world. Social changes imply different lifestyles in each culture. Lifestyles influence the myths used by people in their consumption decisions. The objective of this research is to determine the relationship between lifestyle and coffee consumption habits, from the perspective of myth, in the inhabitants of the Mexican municipalities of Orizaba, Tehuipango, and Zongolica. A survey was conducted with a sample of inhabitants of the three municipalities studied. The statistical analyzes applied were the central limit theorem, Pearson, and Chi-square. The results show that the variables Consumption habits-Lifestyle-Myth, are highly dependent on the level of perception of people. It is concluded that the coffee myth corresponds to the "family union" in the study municipalities. This myth is not characterized in the evolutionary stages contemplated in the "waves of coffee"
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