CALIDAD DE AGUA PARA RIEGO AGRÍCOLA EN EL AGUA SUBTERRÁNEA DE LA ZONA ÁRIDA DEL SUROESTE DE TAMAULIPAS, MÉXICO

The territory of México is made up by two thirds arid and semiarid ecosystems, which influences the quantity and quality of water that infiltrates and reaches aquifers; likewise, the elements present in the water are the result of processes of chemical weathering of the rocks in contact with the water. The objective was to determine the quality of water for agricultural irrigation in the underground water, for which 15 points of sampling were selected that included waterwheels, wells and springs, defining with the Riverside norms the calculation of the relationship of sodium adsorption and, using the Wilcox method of sodium %, where in general terms 46.6 % of the samples of water were of good quality for agricultural irrigation, and 13.3 % presented a doubtful to mediocre quality, which is why it is not recommended for use in agricultural irrigation.El territorio de México está constituido por dos terceras partes de ecosistemas áridos y semiáridos, lo cual influye en la cantidad y calidad de agua que se infiltra y llega a los acuíferos, asimismo los elementos presentes en el agua son resultado de procesos de intemperismo químico de las rocas al contacto con el agua. El objetivo fue determinar la calidad de agua para riego agrícola en el agua subterránea, para lo cual se seleccionaron 15 puntos de muestreo que incluyeron norias, pozos y manantiales, determinando con las normas Riverside el cálculo de la relación de adsorción de sodio y utilizado el método de Wilcox, de % de sodio, donde en términos generales 46.6% de las muestras de agua fueron de buena calidad para riego agrícola, y 13.3% presentaron calidad dudosa a mediocre, por lo cual no se recomienda usarla para el riego agrícola

Evolution Of The Electronic Specific Heat Of (la1-xcex)3al

The specific heat of (La1-xCex)3Al was measured in the temperature range from 2 to 30 K as function of the Ce concentration. The electronic specific heat for small x is close to the normal metal value (14 mJ/K2 mol f.u.), increasing to a maximum of 410 mJ/K2 mol Ce for x∼0.4. characterizing a heavy-fermion behavior around this concentration. Above this critical concentration, the electronic specific heat decreases to 140 mJ/K2 mol Ce for x= 1. From the fitting of the experimental data to Debye and Schottky type Kondo and crystal field contributions we estimated the Kondo temperature. θD, Δ1, and Δ2. Tk was found to increase with Ce concentration. Our results are interpreted in view of the competition between Kondo effect and Ruderman-Kittel-Kasuya-Yosida interaction, © 1997 American Institute of Physics.818 PART 2A41794181Blanco, J.A., De Podesta, M., Espeso, J.I., GomezSal, J.C., Lester, C., McEwen, K.A., Patrikios, N., Fernandez, J.R., (1994) Phys. Rev. B, 49, p. 15126Suzuki, T., Aoki, Y., Nishigori, S., Fujita, T., Murashita, Y., Sakurai, J., (1990) J. Magn. Magn. Mater., 90-91, p. 482Sakurai, J., Murashita, Y., Aoki, Y., Fujita, T., Takabatake, T., Fujii, H., (1989) J. Phys. Soc. Jpn., 58, p. 4078Chen, Y.Y., Lawrence, J.M., Thompson, J.D., Willis, J.O., (1989) Phys. Rev. B, 40, p. 10766Buschow, K.H.J., (1965) Philips Res. Rep., 20, p. 337Evans, S.M.M., Bhattacharjee, A.K., Coqblin, B., (1991) Physica B, 171, p. 293Brandt, N.B., Muschkovich, V.V., (1984) Adv. Phys., 33, p. 373Rajan, V.T., (1983) Phys. Rev. Lett., 51, p. 308Sereni, J.G., (1995) Physica B, 215, p. 273Bredl, C.D., Steglich, F., Schotte, K.D., (1978) Z. Phys. B, 29, p. 32

Magnetization And Specific Heat In U 1-xla Xga 2 And Magnetocaloric Effect In Uga 2

We have investigated the properties of the ferromagnetic series U1-x Lax Ga2. The magnetization results show a reduction of μeff and of Tc when x is increased. The electronic coefficient γ of the specific heat increases to a maximum of 260 mJUmol K2 at x=0.75. This behavior is probably consequence of delocalization of 5f electrons, causing enhancement of the density of states. For x=0.9 the ordering disappears and a non-Fermi-liquid behavior is observed. U Ga2 also presented a significant magnetocaloric effect of Δ Smag =-3.5 Jkg K at 120 K and H=7 T which can be modified by chemical pressure. © 2005 American Institute of Physics.9710Andeev, A.V., Belov, K.P., Deriagin, A.V., Levitin, R.Z., Menovsky, A., (1979) J. Phys. Colloq., 4, p. 82Da Silva, L.M., Gandra, F.G., Rojas, D.P., Cardoso, L.P., Medina, A.N., (2002) Physica B, 312-313, p. 906Tran, V.H., Kaczorowski, D., Roisnel, T., Tróc, R., Noel, H., Bouŕe, F., Andŕ, G., (1995) Physica B, 205, p. 24Gandra, F.G., Rojas, D.P., Shlyk, L., Cardoso, L.P., Medina, A.N., (2001) J. Magn. Magn. Mater., 226, p. 1312Barbara, B., (1973) J. Phys. (Paris), 34, p. 1039Sechovsky, V., Havela, L., Svoboda, P., (1986) J. Less-Common Met., 121, p. 163Segal, E., Wallace, W.E., (1975) J. Solid State Chem., 13, p. 201Radwanski, R.J., Kim-Ngan, N.H., (1995) J. Magn. Magn. Mater., 140, p. 1373Zapf, V.S., Dickey, R.P., Freeman, E.J., Sirvent, C., Maple, M.B., (2002) Phys. Rev. B, 65, p. 024437Pecharsky, V.K., Gschneider Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Pecharsky, V.K., Gschneider Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Plackowski, T., Junod, A., Bouquet, F., Sheikin, I., Wang, Y., Jezÿowski, A., Mattenberger, K., (2003) Phys. Rev. B, 67, p. 184406Svobodaa, P., Sechovsky, V., Menovsky, A.A., (2003) Physica B, 339, p. 177Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M.G., Gandra, F.G., Von Ranke, P.J., De Oliveira, N.A., Phys. Rev. Lett

Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum

We report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the `ankle' at $\lg(E/{\rm eV})=18.5-19.0$ differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass $A > 4$. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report Numbe

The Pierre Auger Observatory Status And Latest Results

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Astrophysical Interpretation Of Pierre Auger Observatory Measurements Of The Uhecr Energy Spectrum And Mass Composition

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Evidence For A Mixed Mass Composition At The ‘ankle’ In The Cosmic-ray Spectrum

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